CHANGES.md

Release 2.5 (summer 2023?) -- compared to 2.4

New minimum dependencies and compatibility changes:

⛰️ New features and public API changes:

• TextureSystem color management: #3761 (2.5.1.0)
  • TextureOpt and TextureOptBatch have a new field, colortransformid, which supplies an integer ID for a requested color space transformation to be applied as texture tiles are read. The default value 0 means no transformation because the texture is presumed to be in the working color space (this is the old behavior, and most performant). Tiles from the same texture file but using different color transformations are allowed and will not interfere with each other in the cache.
  • New TextureSystem::get_colortransform_id(from, to) maps from/to named color spaces to a color transform ID that can be passed to texture lookup calls.
  • ImageCache::get_image_handle and TextureSystem::get_texture_handle now take an optional TextureOpt* parameter that can supply additional constraints (such as color transformation) that TS/IC implementations may wish to split into separate handles. This is currently not used, but is reserved so that the API doesn't need to be changed if we use it in the future.
  • texture.h defines symbol OIIO_TEXTURESYSTEM_SUPPORTS_COLORSPACE that can be tested for existence to know if the new fields are in the TextureOpt structure.
• ImageBufAlgo additions:
  • A new flavor of ociodisplay() now contains an inverse parameter. #3650 (2.5.0.0)
• oiiotool new commands and features:
  • New --iccread and --iccwrite add an ICC profile from an external file to the metadata of an image, or extract the ICC profile metadata and save it as a separate file. #3550 (2.5.0.0)
  • New expression syntax for retrieving metadata {TOP[foo]} is similar to the existing {TOP.foo}, if there is no foo metadata found, the former evaluates to an empty string, whereas the latter is an error. #3619 (2.4.5/2.5.0.0)
  • New --no-error-exit causes an error to not exit immediately, but rather to try to execute the remaining command line operations. This is intended primarily for unit tests and debugging. #3643 (2.5.0.0)
  • New --colorconfiginfo prints the full inventory of color management information, including color space aliases, roles, and with improved readability of output for larger configs. #3707 (2.5.0.0)
  • The --resize command takes new optional :from=, :to=, and :edgeclamp= modifiers to give more general and fine control over the specific correspondence between display windows in the input image and resized destination image (including allowing partial pixel offsets). #3751 #3752 (2.5.0.1)
  • oiiotool: Expression eval NIMAGES gives current stack depth #3822 (2.5.2.0)
  • oiiotool: --parallel-frames parallelizes execution over a frame range rather than over regions within each image operation. This should be used with caution, as it will give incorrect results for an oiiotool command line involving a frame range where the iterations have a data dependency on each other and must be executed in order. But in cases where the order of frame processing doesn't matter and there are many more frames in the sequence than cores, you can get a substantial performance improvement using this flag. #3849 (2.5.2.0)
  • oiiotool: New -otex optional modifier forcefloat=0 can improve memory use for enormous texture conversion. #3829 (2.5.2.0)
• OIIO::getattribute() new queries:
  • font_list, font_file_list, font_dir_list return, respectively, the list of fonts that OIIO found, the list of full paths to font files, and the list of directories searched for fonts. All return a single string that is a semicolon-separated list of the items. #3633 (2.5.0.0)
  • opencolorio_version returns the human-readable (e.g. "2.2.0") version of OpenColorIO that is being used. #3662 (2.5.0.0)
• IOProxy support for additional file formats: SGI #3641, RLA #3642, IFF #3647 (2.5.0.0)
• New OIIO::print() exposes Strutil::print() in the main OIIO namespace. #3667 (2.4.6/2.5.0.0)
• Extensive support for OpenColorIO 2.2 functionality and improved color management:
  • When building against OCIO 2.2, you can specify/use the new "built-in" configs, including using ocio://default, which will automatically be usd if no config is specified and the $OCIO variable is not set #3662 #3707 (2.5.0.0)
  • OIIO tries to find and honor the common color space aliases "scene_linear", "srgb", "lin_srgb", and "ACEScg". When building against OCIO 2.2+, it will know which of any config's color spaces are equivalent to these, even if they are named something totally different, thanks to the magic of OCIO 2.2 built-in configs. For older OCIO (2.1 or older), it is less robust and may have to make best guesses based on the name of the color spaces it finds. #3707 (2.5.0.0)
  • New ColorConfig methods: getAliases() #3662; isColorSpaceLinear() #3662; resolve(name) turns any color space name, alias, role, or OIIO name (like "sRGB") into a canonical color space name; equivalent(n1,n2) returns true if it can tell that the two names refer, ultimately, to equivalent color spaces #3707 (2.5.0.0)
  • New ImageSpec::set_colorspace() method is a more thorough way to set the color space data than simply setting the "oiio:ColorSpace" metadata (though it also does that). #3734 (2.5.0.1)
  • Improve OIIO's ability to guess which of the config's color space names are aliases for common spaces such as srgb, lin_srgb, and acescg (quite robustly if using OCIO >= 2.2, even for totally nonstandard names in the config). #3755 (2.5.0.1)
  • New ColorConfig::getColorSpaceIndex() looks up a color space index by its name, alias, or role. #3758 (2.5.0.1)
• ImageInput / ImageOutput
  • New ImageOutput::check_open() can be used by format writers authors to centralize certain validity tests so they don't need to be implemented separately for each file type. This is not meant to be called by client application code, only by format writer authors. #3686 (2.5.0.0)
  • ImageInput: [breaking] Add an ImageInput::valid_file(IOProxy) overload #3826 (by Jesse Y) (2.5.2.0)
  • ImageInput: Implement valid_file(IOProxy) overloads for DDS, PSD, and WEBP #3831 (by Jesse Y) (2.5.2.0)

Performance improvements:

• Fixed some ImageBuf and IBA internals to avoid unnecessary/redundant zeroing out of newly allocated buffer memory. #3754 (2.5.0.1)
• oiiotool: --parallel-frames parallelizes execution over a frame range rather than over regions within each image operation. This should be used with caution, as it will give incorrect results for an oiiotool command line involving a frame range where the iterations have a data dependency on each other and must be executed in order. But in cases where the order of frame processing doesn't matter and there are many more frames in the sequence than cores, you can get a substantial performance improvement using this flag. #3849 (2.5.2.0)
• psd: Improve memory efficiency of PSD read #3807 (2.5.2.0)
• Improvements to performance and memory when making very large textures #3829 (2.5.2.0)

🐛 Fixes and feature enhancements:

• Python bindings:
  • Now has the ability to getattribute() of int64 and uint64 metadata. #3555 (2.5.0.0)
  • Fixed ability to add and retrieve uint8[] metadata, which on the python side will be numpy arrays of type uint8 (dtype='B'). This is important for being able to set and retrieve "ICCProfile" metadata. #3556 (2.5.0.0)
  • Improve error messages for when passing incorrect python array sizes. #3801 (2.5.1.0)
• ImageBuf improvements:
  • Fixes to subtle bugs when ImageBuf is used with IOProxy. #3666 (2.4.6/2.5.0.0)
• ImageBufAlgo improvements:
  • IBAPrep should not zero out deep images when creating a new destination image. #3724 (2.5.0.0/2.4.8.0)
• make_texture() / maketx / TextureSystem / ImageCache:
  • Ensure proper setting of certain metadata when using a texture as a source to build another texture. #3634 (2.4.5/2.5.0.0)
  • Minor improvements in statistics printing for IC. #3654 (2.5.0.0)
  • When creating a texture, don't overwrite an existing DateTime metadata in the source file. #3692 (2.5.0.0)
  • Fix environment mapping in batch mode when >4 channels are requested in a lookup. #3694 (2.5.0.0)
  • Fixed maketx --lightprobe, which never worked properly for images that weren't float pixel data type. #3732 (2.5.0.0/2.4.7.0)
  • Fix bad handling of maketx --cdf, which was trying to take an extra command line argument that it didn't need. #3748 (2.5.0.1)
  • Improve IC statistics appearance by omitting certain meaningless stats when no files were read by the IC/TS. #3765 (2.4.9.0/2.5.0.1)
  • Fixes that avoid deadlock situations on the file handle cache in certain scenarios with very high thread contention. #3784 (2.4.10.0/2.5.0.3)
  • maketx and oiiotool --otex: Add support for CDFs of bumpslopes channels. Previously, if you used both --bumpslopes and --cdf at the same time, the CDFs were not produced for all channels. #3793 (2.4.10.0/2.5.1.0)
• oiiotool improvements:
  • --printinfo now takes new optional modifiers: :native=1 ensures that the metadata printed is of the file, not changed by the way the image is stored in memory (for example, it may have been converted to a more convenient in-memory data type); :verbose=1 prints verbose stats even if -v is not used; :stats=1 prints full pixel stats, even if --stats is not used. #3639 (2.5.0.0)
  • Expression substitution recognizes new metadata names: nativeformat is the pixel data format of the file, whereas the existing format has always returned the data type used in memory. Also, METANATIVE and METANATIVEBRIEF are the full metadata keywords for native file metadata, comapred to the previously existing META and METABRIEF which we now clarify reflect the in-memory representation. #3639 (2.5.0.0)
  • When -q (quiet mode) is used, and when an error occurs, only print the error message and not the full help message. #3649 (2.5.0.0)
  • --ociodisplay now takes an optional :inverse=1 modifier. #3650 (2.5.0.0)
  • Fix problems with --point when there is no alpha channel. #3684 (2.4.6/2.5.0.0)
  • --dumpdata fix channel name output. #3687 (2.4.6/2.5.0.0)
  • --help now prints a much abbreviated color management section (just the OCIO version and config file). Use the new --colorconfiginfo argument to print the full color management information, which is both more readable and more detailed than what --help used to print. #3707 (2.5.0.0)
  • oiiotool: Don't propagate unsupported channels #3838 (2.5.2.0)
  • refactor: Get rid of the global Oiiotool singleton. #3848 (2.5.2.0)
• ICC Profiles found in JPEG, JPEG-2000, PSN, PSD, and TIFF files are now examined and several key fields are extracted as separate metadata. #3554 (2.5.0.0)
• BMP:
  • Fix reading 16bpp images. #3592 (2.4.5/2.5.0.0)
  • Protect against corrupt pixel coordinates. (TALOS-2022-1630, CVE-2022-38143) #3620 (2.4.5/2.5.0.0)
  • Fix possible write errors, fixes TALOS-2022-1653 / CVE-2022-43594, CVE-2022-43595. #3673 (2.4.6/2.5.0.0)
  • Mark color space as sRGB, which seems likely to be true of any BMP files anybody encounters. #3701 (2.5.0.0)
• DDS:
  • Fix heap overflow in DDS input. #3542 (2.5.0.0)
  • Improved support for DTX5, ATI2/BC5 normal maps, R10G10B10A2 format, RXGB, BC4U, BC5U, A8, improved low bit expansion to 8 bits. #3573 (2.4.4.2/2.5.0.0)
  • Fix alpha/luminance files, better testing. #3581 (2.4.5/2.5.0.0)
  • Optimize loading of compressed images, improves 3-5x. #3583 #3584 (2.4.5/2.5.0.0)
  • Fix crashes for cubemap files when a cube face was not present, and check for invalid bits per pixel. (TALOS-2022-1634, CVE-2022-41838) (TALOS-2022-1635, CVE-2022-41999) #3625 (2.4.5/2.5.0.0)
• DPX:
  • Fix possible write errors, fixes TALOS-2022-1651 / CVE-2022-43592 and TALOS-2022-1652 / CVE-2022-43593. #3672 (2.4.6/2.5.0.0)
• FITS:
  • Ensure that the file is closed if open fails to find the right magic number. #3771 (2.5.1.0)
• GIF:
  • Fix potential array overrun when writing GIF files. #3789 (2.4.10.0/2.5.1.0)
  • Prevent heap-buffer-overflow #3841 (2.5.2.0) (by xiaoxiaoafeifei)
• HDR:
  • Fix a 8x (!) read performance regression for HDR files that was introduced in OIIO in 2.4. On top of that, speed up by another 4x beyond what we ever did before by speeding up the RGBE->float conversion. #3588 #3590 (2.4.5/2.5.0.0)
• IFF:
  • Protect against 0-sized allocations. #3603 (2.5.0.0)
  • IOProxy support. #3647 (2.4.6/2.5.0.0) FIXME Temporarily disable IOProxy support to avoid bugs in #3760 (2.5.0.1)
  • Fix possible write errors, fixes TALOS-2022-1654 / CVE-2022-43596, TALOS-2022-1655 / CVE-2022-43597 CVE-2022-43598, TALOS-2022-1656 / CVE-2022-43599 CVE-2022-43600 CVE-2022-43601 CVE-2022-43602 #3676 (2.4.6/2.5.0.0)
• JPEG
  • jpeg: Fix density calculation for jpeg output #3861 (2.5.2.0) (by Loïc Vital)
• OpenEXR:
  • Fix potential use of uninitialized value when closing. #3764 (2.5.0.1)
  • exr: Try to improve exr thread pool weirdness #3864 (2.5.2.0)
  • Controlled shutdown of IlmThread pool in all apps in which we use it. #3805 (2.5.2.0)
• PBM:
  • Fix accidental inversion for 1-bit bipmap pbm files. #3731 (2.5.0.0/2.4.8.0)
• PNG:
  • Fix memory leaks for error conditions. #3543 #3544 (2.5.0.0)
  • Add EXIF write support to PNG output. #3736 (2.5.0.1)
• PSD:
  • Fix a PSD read error on ARM architecture. #3589 (2.4.5/2.5.0.0)
  • Protect against corrupted embedded thumbnails. (TALOS-2022-1626, CVE-2022-41794) #3629 (2.4.5/2.5.0.0)
  • Fix thumbnail extraction. #3668 (2.4.6/2.5.0.0)
  • When reading, don't reject padded thumbnails. #3677 (2.4.6/2.5.0.0)
  • Fix wrong "oiio:UnassociatedAlpha" metadata. #3750 (2.5.0.1)
  • Handle very wide images with more than 64k resolution in either direction. #3806 (2.5.1.0/2.4.11)
  • psd: Improve memory efficiency of PSD read #3807 (2.5.2.0)
• RAW:
  • Add color metadata: pre_mul, cam_mul, cam_xyz, rgb_cam. #3561 #3569 #3572 (2.5.0.0)
  • Update Exif orientation if user flip is set. #3669 (2.4.6/2.5.0.0)
  • Correctly handle 1-channel raw images. #3798 (2.5.1.0/2.4.11.0)
  • Fix LibRaw flip to Exif orientation conversion #3847 #3858 (2.5.2.0) (by Loïc Vital)
• RLA:
  • Fix potential buffer overrun. (TALOS-2022-1629, CVE-2022-36354) #3624 (2.4.5/2.5.0.0)
  • IOProxy support. #3642 (2.5.0.0)
• SGI:
  • IOProxy support. #3641 (2.5.0.0)
• Targa:
  • Fix incorrect unique_ptr allocation. #3541 (2.5.0.0)
  • Fix string overflow safety. (TALOS-2022-1628, CVE-2022-41981) #3622 (2.4.5/2.5.0.0)
  • Guard against corrupted tga files Fixes TALOS-2023-1707 / CVE-2023-24473, TALOS-2023-1708 / CVE-2023-22845. #3768 (2.5.1.0/2.4.8.1)
• TIFF:
  • Guard against corrupt files with buffer overflows. (TALOS-2022-1627, CVE-2022-41977) #3628 (2.4.5/2.5.0.0)
  • Guard against buffer overflow for certain CMYK files. (TALOS-2022-1633, CVE-2022-41639) (TALOS-2022-1643, CVE-2022-41988) #3632 (2.4.5/2.5.0.0)
  • While building against the new libtiff 4.5, use its new per-tiff error handlers to ensure better thread safety. #3719 (2.5.0.0/2.4.8.0)
  • Better logic for making TIFF PhotometricInterpretation tag and oiio:ColorSpace metadata correspond to each other correctly for TIFF files. #3746 (2.5.0.1)
  • Fix: race condition in TIFF reader, fixes TALOS-2023-1709 / CVE-2023-24472. #3772 (2.5.1.0/2.4.8.1)
  • Disable writing TIFF files with JPEG compression -- it never worked properly and we can't seem to fix it. The fact that nobody noticed that it never worked is taken as evidence that nobody needs it. If asked for, it just uses the default ZIP compression instead. The TIFF reader can still read JPEG-compressed TIFF files just fine, it's only writing that appears problematic. #3791 (2.5.0.4)
• Zfile:
  • Zfile write safety, fixes TALOS-2022-1657 / CVE-2022-43603. #3670 (2.4.6/2.5.0.0)
• Exif / TIFF/JPEG/PSD: Fix EXIF bugs where corrupted exif blocks could overrun memory. (TALOS-2022-1626, CVE-2022-41794) (TALOS-2022-1632, CVE-2022-41684) (TALOS-2022-1636 CVE-2022-41837) #3627 (2.4.5/2.5.0.0)
• Exif / TIFF/JPEG/PSD: Fix typo that prevented us from correctly naming Exif "CameraElevationAngle" metadata. #3783 (2.4.10.0/2.5.1.0)
• Fix missing OIIO::getattribute support for limits:channels and limits:imagesize_MB. #3617 (2.4.5/2.5.0.0)
• IBA::render_text and oiiotool --text now can find ".ttc" font files. #3633 (2.5.0.0)
• Fix ImageOutput::check_open error conditions. #3769 (2.5.1.0)
• Fix thread safety issue when reading ICC profiles from multiple files simultaneously. This could affect any files with ICC profiles. #3767 (2.5.1.0)
• Improve searching for fonts for the text rendering functionality. #3802 #3803 (2.5.1.0)

• OpenCV: Improve OpenCV support -- errors, version, half #3853 (2.5.2.0)
• Prevent possible deadlock when reading files with wrong extensions #3845

🔧 Internals and developer goodies

• filesystem.h:
  • Add an optional size parameter to read_text_file() to limit the maximum size that will be allocated and read (default to a limit of 16MB). New read_text_from_command() is similar to read_text_file, but reads from the console output of a shell command. #3635 (2.5.0.0)
  • New Filesystem::is_executable() and find_program(). #3638 (2.4.6/2.5.0.0)
  • Change IOMemReader constructor to take a const buffer pointer. #3665 (2.4.6/2.5.0.0)
  • IOMemReader::pread now detects and correctly handles out-of-range read positions. #3712 (2.4.7/2.5.0.0)
• fmath.h:
  • Fix a wrong result with fast_exp2() with MSVS and sse4.2. #3804 (2.5.1.0/2.4.11)
• platform.h:
  • New macros for detecting MSVS 2019 and 2022. #3727 (2.5.0.0/2.4.8.0)
• simd.h:
  • Fixes to ensure safe compilation for Cuda. #3810 (2.5.1.0/2.4.11)
• span.h:
  • cspan<> template now allows for Extent template argument (as span<> already did). #3685 (2.5.0.0)
  • New custom fmt formatter can print spans. #3685 (2.5.0.0)
• strutil.h:
  • Add a new flavor of utf16_to_utf8() to convert between std::u16string and std::string (UTF-8 encoded). Note the contrast between this and the existing flavor that takes a std::wstring with UTF-16 encoding (std::wchar/wstring is not guaranteed to 16 bits on all platforms, but u16char/u16string is). #3553 (2.5.0.0)
  • New trimmed_whitspace(). #3636 (2.4.5/2.5.0.0)
  • strutil: Use forward properly for sync::print(). #3825 (2.5.2.0)
• timer.h:
  • Minor improvements to Timer and LoggedTimer classes. #3753 (2.5.0.1)
• tiffutils.h:
  • decode_icc_profile extracts several fields from an ICC profile binary blob and adds them as metadata to an ImageSpec. #3554 (2.5.0.0)
• typedesc.h:
  • Extend TypeDescFromC template to the full set of pixel types. #3726 (2.5.0.0/2.4.8.0)
• ustring.h:
  • Make std::hash work for ustring, add operator< for ustringhash, add from_hash() to ustringhash, make ustringhash == and != be constexpr for C++17 and beyond. #3577 (2.4.5/2.5.0.0)
  • Custom fmt formatter for ustringhash that prints the string rather than the hash. #3614 (2.4.5/2.5.0.0)
  • Ensure that ustring hashes are always 64 bits, even on 32-bit architectures. #3606 (2.5.0.0)
  • Ensure safe use of this header from Cuda. #3718 (2.4.7/2.5.0.0)
  • ustringhash: Make an explicit constructor from a hash value. #3778 (2.4.9.0/2.5.1.0)
• Safety: excise the last instances of unsafe sprintf. #3705 (2.5.0.0)

• Root out stray uses of deprecated simd type names; OIIO_DISABLE_DEPRECATED #3830 (2.5.2.0)

🏗 Build/test/CI and platform ports:

• CMake build system and scripts:
  • It is now possible to -DOpenImageIO_VERSION to override the version number being built (use with extreme caution). #3549 #3653 (2.5.0.0)
  • Perform parallel builds with MSVS. #3571 (2.5.0.0)
  • New CMake cache variable FORTIFY_SOURCE, if enabled, builds with the specified gcc _FORTIFY_SOURCE option defined. This may be desirable for people deploying OIIO in security-sensitive environments. #3575 (2.4.5/2.5.0.0)
  • CMake config should not include a find of fmt if it's internalized. #3739 (2.4.7.1/2.5.0.0)
  • New CMake cache variable OIIO_DISABLE_BOOST_STACKTRACE to disable the stacktrace functionality for users who want to avoid the Boost stacktrace library. #3777 (2.4.9.0/2.5.1.0)
  • Check need for libatomic with check_cxx_source_compiles instead of the more expensive check_cxx_source_runs. #3774 (2.4.9.0/2.5.1.0)
  • Fix incorrect CMake variable name to control symbol visibility #3834 (2.5.2.0)
• Dependency version support:
  • Support for OpenColorIO 2.2. #3644 (2.5.0.0)
  • New CMake option INTERNALIZE_FMT (default ON), if set to OFF, will force OIIO clients to use the system fmt library and will not copy the necessary fmt headers into the OIIO include area. #3598 (2.4.7/2.5.0.0)
  • build_libtiff.bash changed to build shared library by default. #3586 (2.5.0.0)
  • build_openexr.bash changed to build v3.1.5 by default. #3703 (2.5.0.0)
  • Qt6 support for iv. #3779 (2.4.9.0/2.5.1.0)
  • Fmt 10.0 support #3836 (2.5.2.0)
  • Ffmpeg 6.0 support #3812 (2.5.2.0)
  • Disable new warning for fmt headers in gcc13 #3827 (2.5.2.0)
• Testing and Continuous integration (CI) systems:
  • Restored sanitizer tests which had been inadvertently disabled. #3545 (2.5.0.0)
  • Added tests for undefined behavior sanitizer. #3565 (2.5.0.0)
  • Added tests or improved test coverage for Cineon files #3607, iinfo #3605 #3613 #3688 #3706, texture statistics #3612, oiiotool unit tests #3616, oiiotool expression substitution #3636, various oiiotool #3637 #3643 #3649, oiiotool control flow #3643, oiiotool sequence errors and selecting out of range subimages or mip levels #3649, Strutil functionality #3655, ImageCache #3654, environment mapping #3694, texture3d #3699, term output #3714, igrep #3715, oiiotool --pdiff #3723, zover, fixnan for deep images, 2D filters #3730, pbm files #3731, maketx --lightprobe #3732 (2.5.0.0), TypeDesc::tostring, python ImageCache and ImageBuf #3745, maketx #3748 (2.5.0.1), ImageBufAlgo python functions #3766 (2.5.1.0).
  • Make testsuite/oiiotool-control run much faster by combining commands into fewer oiiotool invocations (speeds up testsuite) #3618 (2.5.0.0)
  • CI color related tests use the OCIO buit-in configs, when OCIO 2.2+ is available. #3662 (2.5.0.0)
  • ci: Fix warnings #3833 (2.5.2.0)
  • ci: Fix package name for icc #3860 (2.5.2.0)
  • Change the few symbolic links to copies to help Windows #3818 (2.5.2.0)
  • Fix incorrect branch name when cloning openexr-images for the tests #3814 (2.5.2.0) (by Jesse Y)
• Platform support:
  • MinGW: fix incorrect symbol visibility issue for ImageBuf iterators. #3578 (2.4.5/2.5.0.0)
  • Windows: protect against OpenEXR thread deadlock on shutdown. #3582 (2.4.5/2.5.0.0)
  • Windows: Work around a static destruction order issue. #3591 (2.4.5/2.5.0.0)
  • Windows: define NOGDI to keep the inclusion of windows.h from adding as many unneeded symbols. #3596 (2.4.5/2.5.0.0)
  • Windows: Stop including Windows.h from public OIIO headers. #3597 (2.5.0.0)
  • ARM: improve SIMD operations for ARM NEON. #3599 (2.4.5/2.5.0.0)
  • Windows on ARM64 build fixes. #3690 (2.4.6/2.5.0.0)
  • Mac: Suppress warnings about deprecated std::codecvt on newest Apple clang. #3709 #3710 (2.4.7/2.5.0.0)
  • ARM: Fix signed/unsigned mismatch compiler errors in vbool4 methods. #3722 (2.4.7/2.5.0.0)
  • ARM Mac: Fix build break. #3735 (2.5.0.0/2.4.7.1)
  • Windows: Fix unresolved external symbol for MSVS 2017. #3763 (2.5.0.1)
  • Fixes to make a clean build on Mac using Apple Clang 11.0. #3795 (2.4.10.0/2.5.1.0)
  • Fixes to build properly on OpenBSD. #3808 (2.5.1.0/2.4.11)
  • Mac: Fixes for latest xcode on MacOS 13.3 Ventura #3854 (2.5.2.0)
  • Fix build error with MSVC #3832 (by Ray Molenkamp) (2.5.2.0)

📚 Notable documentation changes:

• Added RELEASING.md documenting our versioning and release procedures #3564 #3580
• Docs: Better Windows build instructions in INSTALL.md. #3602 (2.4.5/2.5.0.0)
• Update CONTRIBUTING and SECURITY #3852 (2.5.2.0)

Release 2.4.12.0 (1 June 2023) -- compared to 2.4.11.1

• oiiotool: Don't propagate unsupported channels #3838
• Improvements to performance and memory when making very large textures #3829
• fix: Prevent possible deadlock when reading files with wrong extensions #3845
• gif: Prevent possible heap buffer overflow #3841 (by xiaoxiaoafeifei)
• psd: Improve memory efficiency of PSD read #3807
• raw: Fix LibRaw flip to Exif orientation conversion #3847 (by Loïc Vital)
• raw: Raw input fix user_flip usage #3858 (by Loïc Vital)
• strutil: Use forward properly for sync::print(). #3825
• build: Fixes for latest xcode on MacOS 13.3 Ventura #3854
• build: Fix build error with MSVC #3832 (by Ray Molenkamp)
• ci: Fix warnings #3833
• ci: Fix package name for icc #3860

Release 2.4.11.1 (14 May 2023) -- compared to 2.4.11.0

• build: Fmt 10.0 support #3836

Release 2.4.11.0 (1 May 2023) -- compared to 2.4.10.0

• oiiotool: For expression evaluation, NIMAGES now evaluates to the current image stack depth. #3822
• Python: Improve error messages when passing wrong python array sizes. #3801
• Raw: handle 1-channel raw images. #3798
• HEIC: Support the ".hif" extension, which seems to be used by some Canon cameras instead of .heif. #3813
• PSD: Fix problems reading images with width > 64k pixels. #3806
• Windows/fmath: Work around MSVS bug(?) that generated wrong code for fast_exp2. #3804
• Build: Fix building on OpenBSD. #3808
• Build: Refactor simd.h to disable Intel intrinsics when not on Intel (including Cuda compiles). #3814
• Build: Fix building against new ffmpeg 6.0. #3812
• Build: Work around problems with fmt library + NVPTX relating to unknown float128 type. #3823
• CI/test: Fix incorrect branch name when cloning openexr-images for the testsuite. #3814
• Test: Use copies instead of symlinks in a couple spots to help on Windows. #3818

Release 2.4.10.0 (1 Apr 2023) -- compared to 2.4.9.0

• Exif: Fix typo that prevented us from correctly naming Exif "CameraElevationAngle" metadata. #3783
• IC/TS: Fixes that avoid deadlock situations on the file handle cache in certain scenarios with very high thread contention. #3784
• Docs: Some retroactive edits to INSTALL.md to correctly document changed dependencies of the 2.4 series.
• GIF: Fix potential array overrun when writing GIF files. #3789
• Build: Fixes to make a clean build on Mac using Apple Clang 11.0. #3795
• FYI: This version of OIIO should build against Clang 16.
• maketx: Fix a broken --cdf flag, which was set up to take an argument, but should always simply have acted as a simple boolean flag on its own. The incorrect way it was set up not only was useless, but also could lead to occasional crashes. #3748
• maketx and oiiotool --otex: Add support for CDFs of bumpslopes channels. Previously, if you used both --bumpslopes and --cdf at the same time, the CDFs were not produced for all channels. #3793

Release 2.4.9.0 (1 Mar 2023) -- compared to 2.4.8.1

• Build: check need for libatomic with check_cxx_source_compiles instead of the more expensive check_cxx_source_runs. #3774
• Fix(IC): Avoid bad IC stats when no files were read. #3765
• Build: Add a cmake option OIIO_DISABLE_BOOST_STACKTRACE to disable use and dependency of boost stacktrace. #3777
• ustringhash: Make an explicit constructor from a hash value. #3778
• Build: Add ability to build against Qt6. #3779

Release 2.4.8.1 (13 Feb 2023) -- compared to 2.4.8.0

• Fix(targa): guard against corrupted tga files Fixes TALOS-2023-1707 / CVE-2023-24473, TALOS-2023-1708 / CVE-2023-22845. #3768
• Fix: race condition in TIFF reader, fixes TALOS-2023-1709 / CVE-2023-24472. #3772
• Windows: Fix unresolved external symbol for MSVS 2017 #3763
• Fix: Initialize OpenEXROutput::m_levelmode() in init(). #3764
• Fix: improve thread safety for concurrent tiff loads. #3767
• Fix(fits): Make sure to close if open fails to find right magic number. #3771

Release 2.4.8.0 (1 Feb 2023) -- compared to 2.4.7.1

• oiiotool --pdiff: test, be sure to count it as making output. #3723
• IBAprep should not zero out deep images when creating dst #3724
• PBM: Fix for incorrect inverting of 1-bit pbm images. #3731
• New ImageSpec:set_colorspace() sets color space metadata in a consistent way. #3734
• BMP: set colorspace to sRGB #3701
• PNG: Add EXIF support when writing PNG files. #3735
• PSD: Fix wrong oiio:UnassociatedAlpha metadata for PSD files. #3750
• platform.h: set up macros for detecting MSVS 2019 and 2022 #3727
• typedesc.h: Extend TypeDescFromC template to the full set of pixel types #3726
• Testing: many improvements for testing and code coverage. #3730 #3654 #3694 #3699 #3732 #3741 #3745 #3747
• Testing: Fix long-broken ref images for texture-icwrite test #3733
• Docs: Updated RTD docmentation style, looks much nicer. #3737
• Docs: improve description of ociodisplay and others.
• Docs: Fix old release notes to document all CVEs addressed in certain prior releases.

Release 2.4.7.1 (3 Jan 2023) -- compared to 2.4.7.0

• Fix build break for Mac ARM. #3735
• CMake config should not include a find of fmt if it's internalized. #3739

Release 2.4.7.0 (1 Jan 2023) -- compared to 2.4.6.0

• IOMemReader detects and errors for out-of-range read positions. #3712
• Build/Mac: Suppress some deprecation warnings when building wth the newest Apple clang. #3709 #3710
• ARM: Fix signed/unsigned SIMD mismatch in vbool4::load. #3722
• Build: New CMake variable INTERNALIZE_FMT, when set to OFF will ensure that the fmt headers are not internalized (copied to the installed part of OIIO). The default is ON, matching old behavior. #3598
• Testing: Improved testing of iinfo #3688 #3706, 'term' output #3714, igrep #3715.
• build_openexr.bash: bump default version of OpenEXR/Imath retrieved to be 3.1.5. #3703
• span.h: Make sure the cspan alias also allows the Extent template argument; add a custom formatter to print spans. #3685
• ustring.h: #if guards to let the header be Cuda-safe. #3718
• Internals: refactoring to remove duplicated code for iinfo and oiiotool --info. #3688
• Internals: remove the last instances of unsafe std::sprintf. #3705

Release 2.4.6 (1 Dec 2022) -- compared to 2.4.5.0

• make_texture / maketx : ensure proper setting of certain metadata when using a texture as a source to build another texture. #3634
• Build: Make sure use of ${PROJECT_NAME} doesn't occur before the call to project(). #3651
• Fix null pointer dereference when OCIO no configuration is found. #3652
• Support for building against OpenColorIO 2.2. #3662
• Fixes to subtle bugs when ImageBuf is used with IOProxy. #3666
• oiiotool: Fix problems with --point when there is no alpha channel. #3684
• oiiotool: --dumpdata fix channel name output. #3687
• BMP: Fix possible write errors, fixes TALOS-2022-1653 / CVE-2022-43594, CVE-2022-43595. #3673
• DPX: Fix possible write errors, fixes TALOS-2022-1651 / CVE-2022-43592 and TALOS-2022-1652 / CVE-2022-43593. #3672
• IFF files: Add IOProxy support. #3647
• IFF: Fix possible write errors, fixes TALOS-2022-1654 / CVE-2022-43596, TALOS-2022-1655 / CVE-2022-43597 CVE-2022-43598, TALOS-2022-1656 / CVE-2022-43599 CVE-2022-43600 CVE-2022-43601 CVE-2022-43602 #3676
• PSD: Fix thumbnail extraction. #3668
• PSD: when reading, don't reject padded thumbnails. #3677
• Raw: Update Exif orientation if user flip is set. #3669
• Zfile write safety, fixes TALOS-2022-1657 / CVE-2022-43603. #3670
• filesystem.h: new Filesystem::is_executable() and find_program(). #3638
• filesystem.h: Change IOMemReader constructor to take a const buffer pointer. #3665
• strutil.h: new trimmed_whitspace(). #3636
• New OIIO::print() exposes Strutil::print() in the main OIIO namespace. #3667
• Testing: improved testing of oiiotool #3637 #3643 #3649, Strutil #3655

Release 2.4.5 (1 Nov 2022) -- compared to 2.4.4.2

• oiiotool: new commands --iccread reads a named file and adds its contents as the ICCProfile metadata of the top image, --iccwrite saves the ICCProfile metadata of the top file to a named file. #3550
• TIFF, JPEG, JPEG-2000, PNG, and PSD files containing ICC profiles now extract and report extra metadata related to aspects of those profiles. #3554
• Python: support int8[] metadata and retrieving the ICCPorofile metadata. #3556
• oiiotool: New expression syntax for retrieving metadata {TOP[foo]} is similar to the existing {TOP.foo}, if there is no foo metadata found, the former evaluates to an empty string, whereas the latter is an error. #3619
• Strutil: new utf16_to_utf8(const std::u16string&) and Strutil::utf8_to_utf16wstring(). #3553
• ustring: make std::hash work for ustring, add operator< for ustringhash, add from_hash() to ustringhash, make ustringhash == and != be constexpr for C++17 and beyond. #3577 Custom fmt formatter for ustringhash that prints the string rather than the hash. #3614
• Build: the version number is now a CMake cache variable that can be overridden (caveat emptor). #3549
• Build/security: New CMake cache variable FORTIFY_SOURCE, if enabled, builds with the specified gcc _FORTIFY_SOURCE option defined. This may be desirable for people deploying OIIO in security-sensitive environments. #3575
• CI: testing now includes using undefined behavior sanitizer. #3565
• Windows: protect against OpenEXR thread deadlock on shutdown. #3582
• Windows: Work around a static destruction order issue. #3591
• Windows: define NOGDI to keep the inclusion of windows.h from adding as many unneeded symbols. #3596
• MinGW: fix incorrect symbol visibility issue for ImageBuf iterators. #3578
• ARM: improve SIMD operations for ARM NEON. #3599
• Docs: New RELEASING.md documents our releasing procedures. #3564 #3580
• Docs: Better Windows build instructions in INSTALL.md. #3602
• Fix missing OIIO::getattribute support for limits:channels and limits:imagesize_MB. #3617
• BMP: fix reading 16bpp images. #3592
• BMP: protect against corrupt pixel coordinates. (TALOS-2022-1630, CVE-2022-38143) #3620
• DDS: fix alpha/luminance files, better testing. #3581
• DDS: optimize loading of compressed images, improves 3-5x. #3583 #3584
• DDS: Fix crashes for cubemap files when a cube face was not present, and check for invalid bits per pixel. (TALOS-2022-1634, CVE-2022-41838) (TALOS-2022-1635, CVE-2022-41999) #3625
• HDR: fix a 8x (!) read performance regression for HDR files that was introduced in OIIO in 2.4. #3588 On top of that, speed up by another 4x beyond what we ever did before by speeding up the RGBE->float conversion. #3590
• PNG: fix memory leaks when errors take an early exit. #3543 #3544
• PSD: fix a PSD read error on ARM architecture. #3589
• PSD: protect against corrupted embedded thumbnails. (TALOS-2022-1626, CVE-2022-41794) #3629
• RAW: additional color metadata is now recognized: pre_mul, cam_mul, cam_xyz, rgb_cam. #3561 #3569 #3572
• RLA: fix potential buffer overrun. (TALOS-2022-1629, CVE-2022-36354) #3624
• Targa: string overflow safety. (TALOS-2022-1628, CVE-2022-41981) #3622
• TIFF/JPEG/PSD: Fix EXIF bugs where corrupted exif blocks could overrun memory. (TALOS-2022-1626, CVE-2022-41794) (TALOS-2022-1631, CVE-2022-41649) (TALOS-2022-1632, CVE-2022-41684) (TALOS-2022-1636 CVE-2022-41837) #3627
• TIFF: guard against corrupt files with buffer overflows. (TALOS-2022-1627, CVE-2022-41977) #3628
• TIFF: guard against buffer overflow for certain CMYK files. (TALOS-2022-1633, CVE-2022-41639) (TALOS-2022-1643, CVE-2022-41988) #3632

Release 2.4.4.2 (3 Oct 2022) -- compared to 2.4.4.1

• DDS: Improved support for DTX5, ATI2/BC5 normal maps, R10G10B10A2 format, RXGB, BC4U, BC5U, A8, improved low bit expansion to 8 bits. #3573 (2.4.4.2)
• DDS: Fix possible heap overflow on input. #3542 (2.4.4.2)

Release 2.4 (1 Oct 2022) -- compared to 2.3

New minimum dependencies and compatibility changes:

• OpenEXR minimum is now 2.3 (raised from 2.0). #3109 (2.4.0)
• Field3D support has been removed entirely. The Field3D library appears to be no longer maintained, and is incompatible with modern versions of OpenEXR/Imath. We believe that all prior uses of Field3D use via OIIO have been migrated to OpenVDB. #3151 (2.4.0)

New major features and public API changes:

• Imath header and class hiding:
  • Header includes have been shuffled around so that Imath headers are not included from OIIO headers where they are not needed, and some OIIO headers that need Imath types only for few function parameters now guard those functions with #if so that Imath-taking functions are not visible unless the calling app has previously had an #include of Imath. If your app uses Imath types but did not include the right Imath headers (relying on the accidental fact of other OIIO headers transitively including them), you may need to adjust your includes. #3301 #3332 (2.4.0.2) #3406 #3474 (2.4.2)
  • New V3fParam, M33fParam, and M44fParam (defined in vecparam.h) are used just for parameter passing in public APIs, instead of Imath::V3f, M33f, or M44f, in order to more fully hide Imath types from our public interfaces. These are only parameter-passing classes, and are not useful as vector or matrix classes in their own right. But they seamlessly cast to and from other vector- and matrix-like classes. #3330 (2.4.1.0)
  • OPENIMAGEIO_IMATH_DEPENDENCY_VISIBILITY is a new CMake cache variable at OIIO build time that controls whether the Imath library dependencies will be declared as PUBLIC (default) or PRIVATE target dependencies of libOpenImageIO and libOpenImageIO_Util. #3322 (4.2.0.2) #3339 (4.2.0.3)
  • For downstream projects that consume OIIO's exported cmake config files, setting CMake variable OPENIMAGEIO_CONFIG_DO_NOT_FIND_IMATH to ON will skip the find_depencency() calls for Imath and OpenEXR. To clarify, this is not a variable that has any effect when building OIIO, it's something set in the downstream project itself. #3322 (4.2.0.2)
• The dithering that happens when saving high bit depth image data to low bit depth formats has been improved in several ways. It now applies when writing

  8 bit data to <= 8 bit files, not just when the source is float or half. The dither pattern is now based on blue noise, and this dramatically improves the visual appearance. #3141 (2.4.0/2.3.10)

• TextureSystem now supports stochastic sampling. If the new TextureOpt field rnd (which now defaults to -1.0) is set to a value >= 0, the filtered texture lookup can use stochastic sampling to save work. The shading system attribute "stochastic" is set to the stochastic strategy: 0 = no stochastic sampling; 1 = for trilinear or anisotropic MIP modes, choose one MIP level stochastically instead of blending between two levels; 2 = for anisotropic mode, use just one anisotropic sample, chosen across the filter axis. (This is a bit field, so 3 combines both strategies.) We measure this speeding up texture lookups by 25-40%, though with more visual noise (which should be resolved cleanly by a renderer that uses many samples per pixel). This should only used for texture lookups where many samples per pixel will be combined, such as for surface or light shading. It should not be used for texture lookups that must return a single correct value (such as for displacement, when each grid position is sampled only once). Even when the "stochastic" attribute is nonzero, any individual texture call may be made non-stochastic by setting TextureOpt.rnd to a negative value. #3127 (2.4.0/2.3.10) #3457 (2.4.2)
• maketx/make_texture() now supports options to store Gaussian forward and inverse transform lookup tables in image metadata (must be OpenEXR textures for this to work) to aid writing shaders that use histogram-preserving blending of texture tiling. This is controlled by new maketx arguments --cdf, --cdfsigma, --sdfbits, or for IBA::make_texture() by using hints maketx:cdf, maketx:cdfsigma, and maketx:cdfbits. #3159 #3206 (2.4.0/2.3.10)
• oiiotool new commands and features:
  • Control flow via --if, --else, --endif, --while, --endwhile, --for, --endfor let you prototypes conditional execution and loops in the command sequence. #3242 (2.4.0)
  • --set can set variables and their values can be retrieved in expressions. #3242 (2.4.0)
  • Expressions now support: numerical comparisons via <, >, <=, >=, ==, !=, <=>; logical operators &&, ||, !, not(); string comparison functions eq(a,b) and neq(). #3242 #3243 (2.4.0)
  • --oiioattrib can set "global" OIIO control attributes for an oiiotool run (equivalent of calling OIIO::attribute()). #3171 (2.4.0/2.3.10)
  • --repremult exposes the previously existing IBA::repremult(). The guidance here is that --premult should be used for one-time conversion of "unassociated alpha/unpremultiplied color" to associated/premultiplied, but when you are starting with a premultiplied image and have a sequence of unpremultiply, doing some adjustment in unpremultiplied space, then re-premultiplying, it's --repremult you want as the last step, because it preserves alpha = 0, color > 0 data without crushing it to black. #3192 (2.4.0/2.3.10)
  • --saturate can adjust saturation level of a color image. #3190 (2.4.0/2.3.10)
  • --maxchan and --minchan turn an N-channel image into a 1-channel images that for each pixel, contains the maximum value in any channel of the original for that pixel. #3198 (2.4.0/2.3.10)
  • --point lets you color one or more pixels in an image (analogous to IBA::render_point). #3256 (2.4.0)
  • --warp now takes an optional modifier :wrap=... that lets you set which wrap mode to use when sampling past the edge of the source image. #3341 (2.4.0.3)
  • New --st_warp performs warping of an image where a second image gives the (s,t) coordinates to look up from at every pixel. #3379 (2.4.2/2.3.14)
  • Many attribute actions now take optional modifier :subimages= that instructs oiiotool to apply to a particular subset of subimges in multi-subimage files (such as multi-part exr). The commands so enabled include --attrib, --sattrib, --eraseattrib, --caption, --orientation, --clear-keywords, --iscolorspace. The default, if subimages are not specified, is to only change the attributes of the first subimage, unless -a is used, in which case the default is to change the attributes of all subimages. #3384 (2.4.2)
• ImageSpec :
  • New constructors to accept a string for the data type. #3245 (2.4.0/2.3.12)
• ImageBuf/ImageBufAlgo :
  • IBA::saturate() can adjust saturation level of a color image. #3190 (2.4.0/2.3.10)
  • IBA::maxchan() and minchan() turn an N-channel image into a 1-channel images that for each pixel, contains the maximum value in any channel of the original for that pixel. #3198 (2.4.0/2.3.10)
  • New IBA::st_warp() performs warping of an image where a second image gives the (s,t) coordinates to look up from at every pixel. #3379 (2.4.2/2.3.14)
  • IBA::bluenoise_image() returns a reference to a periodic blue noise image. #3141 #3254 (2.4.0/2.3.10)
• ImageCache / TextureSystem :
  • IC/TS both have added a getattributetype() method, which retrieves just the type of a named attribute. #3559 (2.4.4.0)
• Python bindings:
  • New ImageBuf constructor and reset() from a NumPy array only -- it deduces the resolution, channels, and data type from the array dimensions and type. #3246 (2.4.0/2.3.12)
  • ROI now has a working copy() method. #3253 (2.4.0/2.3.12)
  • ImageSpec and ParamValueList now support 'key' in spec, del spec['key'], and spec.get('key', defaultval) to more fully emulate Python dict syntax for manipulating metadata. #3252 (2.3.12/2.4.0)
  • Support uint8 array attributes in and out. This enables the proper Python access to "ICCProfile" metadata. #3378 (2.4.1.0/2.3.14)
  • New ImageSpec.get_bytes_attribute() method is for string attributes, but in Python3, skips decoding the underlying C string as UTF-8 and returns a bytes object containing the raw byte string. #3396 (2.4.2)
  • Fixes for Python 3.8+ to ensure that it can find the OpenImageIO module as long as it's somewhere in the PATH. This behavior can be disabled by setting environment variable OIIO_LOAD_DLLS_FROM_PATH=0. #3470 (2.4.0/2.3.18)
• New global OIIO attributes:
  • "try_all_readers" can be set to 0 if you want to override the default behavior and specifically NOT try any format readers that don't match the file extension of an input image (usually, it will try that one first, but it if fails to open the file, all known file readers will be tried in case the file is just misnamed, but sometimes you don't want it to do that). #3172 (2.4.0/2.3.10)
  • "use_tbb" if nonzero, and if OIIO was built with TBB enabled and found, then will use the TBB thread pool instead of the OIIO internal thread pool. #3473 (2.4.2.2)
  • "version" (read only) now retrieves the version string. #3534 (2.3.19.0/2.4.2.2)
• Full IOProxy support has been added to TIFF #3075 (2.4.0/2.3.8), JPEG, GIF #3181 #3182 (2.4.0/2.3.10), DDS #3217, PNM #3219, PSD #3220, Targa #3221, WebP #3224, BMP #3223, JPEG-2000 #3226 (2.4.0).
• Convention change: Image readers who wish to convey that the color space of an input image is a simple gamma-corrected space will now call the color space "GammaX.Y" (previously we sometimes used this, but sometimes called it "GammaCorrectedX.Y"). #3202 (2.4.0)
• oiioversion.h now defines symbols OIIO_USING_IMATH_VERSION_MAJOR and OIIO_USING_IMATH_VERSION_MINOR that reveal which Imath version was used internally to OIIO when it was built (which may be different than the version found when the downstream app is being compiled). #3305 (2.4.0.1)
• Most of the major APIs (including ImageInput, ImageOutput, and ImageBuf) that took a std::string or string_view to indicate a filename (assumed to support UTF-8 encoding of Unicode filenames) now have additional versions that directly take a std::wstring, thus supporting UTF-16 Unicode filenames as "wide strings". #3312 #3318 (2.4.0.1)
• The ColorConfig API adds new calls getDisplayViewColorSpaceName() and getDisplayViewLooks() that expose the underlying OpenColorIO functionality. #3319 (2.4.0.2)
• Many long-deprecated functions in imageio.h and imagbufalgo.h are now marked as OIIO_DEPRECATED, and therefore may start to generate warnings if used by downstream software. #3328 (2.4.1.0)

Performance improvements:

• Raise the default ImageCache default tile cache from 256MB to 1GB. This should improve performance for some operations involving large images or images with many channels. #3180 (2.4.0/2.3.10)
• Performance of JPEG-2000 I/O is improved by 2-3x due to multithreading, but only if you are using a sufficiently new version of OpenJPEG (2.2 for encoding, 2.4 for decoding). #2225 (2.3.11/2.4.0)
• Dramatically speed up (50-100x) the implementation of Strutil iequals, iless, starts_with, istarts_with, ends_with, iends_with. This in turn speeds up ParamValueList find/get related methods, ImageSpec find/get methods, and TS::get_texture_info. #3388 (2.4.1.1)
• Renderer users of the TextureSystem might see up to a ~40% speedup if using the new stochastic sampling features. #3127 #3457
• Speed up reading of uncompressed DDS images by about 3x. #3463 (2.4.2.0)

Fixes and feature enhancements:

• ImageSpec:
  • Implemented deserialization of extra_attribs from XML. #3066 (2.4.0/2.3.8)
  • Allow getattribute("format") to retrieve the name of the pixel data type. #3247 (2.4.0)
• ImageInput / ImageOutput:
  • Protected methods that make it easier to implement support for IOProxy in image readers and writers. #3231 (2.4.0)
  • Fix crash when ioproxy is passed to a plugin that doesn't support it. #3453 (2.4.2)
• ImageBuf / ImageBufAlgo:
  • Fix ImageBuf::read bug for images of mixed per-channel data types. #3088 (2.4.0/2.3.8)
  • IBA::noise() now takes "blue" as a noise name. Also, "white" is now the preferred name for what used to be "uniform" (which still works as a synonym). #3141 (2.4.0/2.3.10)
  • Refactor ImageBuf::Iterator, ConstIterator templates, reduces compile time substantially. #3195 (2.4.0)
  • IBA functions taking a cspan<> now more flexibly can be passed an init list like { 0.2f, 0.4f, 0.5f } instead of needing to wrap it in a cspan<float>() constructor. #3257 (2.3.12/2.4.0)
  • make_texture(): ensure that "maketx:ignore_unassoc" is honored. #3269 (2.4.0.1/2.3.12)
  • IBA::computePixelStats() improved precision. #3353 (2.4.1.0/2.3.14)
  • IBA::isConstantColor() is faster -- now if one thread finds its portion not constant, it can signal the other threads to stop immediately instead of completing their regions. #3383 (2.4.1.1)
  • A new flavor of IBA::compare() allows relative as well as absolute error thresholds. #3508 (2.3.19.0/2.4.2.2)
• ImageCache / TextureSystem / maketx:
  • When textures are created with the "monochrome_detect" feature enabled, which turns RGB textures where all channels are always equal into true single channel greyscale, the single channel that results is now correctly named "Y" instead of leaving it as "R" (it's not red, it's luminance). #3205 (2.4.0/2.3.10)
  • Enhance safety/correctness for untiled images that exceed 2GB size (there was an integer overflow problem in computing offsets within tiles). #3232 (2.3.11/2.4.0)
  • Improve error propagation from ImageCache to higher levels, especially for tile-reading errors encountered during ImageBuf iterator use, and ImageCache errors encountered when using the TextureSystem. #3233 (2.4.0)
  • Support an additional UDIM pattern <UVTILE>, which is specified by MaterialX. #3280 #3285 (2.3.12/2.4.0.1)
  • Add support for UDIM pattern <uvtile> (used by Clarisse & V-Ray). #3358 (2.4.1.0/2.3.14)
  • The maketx --handed option, or oiiotool -attrib -otex:handed=..., or adding "handed" metadata to the configuration ImageSpec being passed to IBA::make_texture() is now supported for communicating the handedness of a vector displacement or normal map. #3331 (2.4.0.2)
  • Speed up UDIM lookups by eliminating internal mutex. #3417 (2.4.0)
  • TextureSystem: Fix typo that prevented "max_tile_channels" attribute from being set or retrieved. (2.4.2/2.3.17)
• oiiotool:
  • --ch now has virtually no expense if the arguments require no change to the channel order or naming (previously, it would always incur an image allocation and copy even if no real work needed to be done). #3068 (2.4.0/2.3.8)
  • --ch now warns if you specify a channel name that was not present in the input image. #3290 (2.4.0.1)
  • --runstats timing report has been improved and now more accurately attributes time to each operation. In particular, input I/O is now credited to "-i" rather than being incorrectly attributed to the other ops that happen to trigger I/O of previously mentioned files. #3073 (2.4.0/2.3.8)
  • Allow quotes in command modifiers. #3112 (2.4.0/2.3.9)
  • Fix --dumpdata getting the formatting of floating point values wrong. #3131 (2.4.0/2.3.9)
  • --dumpdata:C=name causes the dumped image data to be formatted with the syntax of a C array. #3136 (2.4.0/2.3.9)
  • --noise now takes "blue" as an additional noise type. #3141 (2.4.0/2.3.10)
  • -d now accepts "uint1", "uint2", "uint4", and "uint6" for formats that support such low bit depths (TIFF). #3141 (2.4.0/2.3.10)
  • --invert fixed to avoid losing the alpha channel values. #3191 (2.4.0/2.3.10)
  • Fix bug when autocropping output images when the entire pixel data window is in the negative coordinate region. #3164 (2.4.0/2.3.10)
  • Improved detection of file reading failures. #3165 (2.4.0/2.3.10)
  • All commands that do filtering (--rotate, --warp, --reize, --fit, and --pixelaspect) now accept optional modifier :highlightcomp=1 to enable "highlight compensation" to avoid ringing artifacts in HDR images with very high-contrast regions. #3239 (2.4.0)
  • --pattern checker behavior has changed slightly: if the optional modifier :width= is specified but :height= is not, the height will be equal to the width. #3255 (2.4.0)
  • --pixelaspect fixes setting of the "PixelAspectRatio", "XResolution", and "YResolution" metadata, they were not set properly before. #3340 (2.4.0.3)
  • Fix bug that prevented metadata from being able to print as XML. #3499 (2.4.2.2)
  • i:ch=... fixes crashes, and also improves the warning message in cases where the requested channels don't exist in the source image. #3513 (2.4.2.2)
• Python bindings:
  • Subtle/asymptomatic bugs fixed in ImageBufAlgo.color_range_check() and histogram() due to incorrect release of the GIL. #3074 (2.4.0)
  • Bug fix for ImageBufAlgo.clamp(): when just a float was passed for the min or max, it only clamped the first channel instead of all channels. #3265 (2.3.12/2.4.0)
  • Fix the ability to getattribute() of int64 and uint64 metadata or attributes. #3555 (2.4.4.0)
• idiff:
  • --allowfailures allows that number of failed pixels of any magnitude. #3455 (2.4.2)
  • --failrelative and --warnrelative allows the failure and warning threshold to use a symmetric mean relative error (rather than the absolute error implied by the existing --fail and --warn arguments). #3508 (2.3.19.0, 2.4.2.2)
• BMP:
  • IOProxy support. #3223 (2.4.0)
  • Support for additional (not exactly fully documented) varieties used by some Adobe apps. #3375 (2.4.1.0/2.3.14)
  • Better detection of corrupted files with nonsensical image dimensions or total size. #3434 (2.4.2/2.3.17/2.2.21)
  • Protect against corrupted files that have palette indices out of bound. #3435 (2.4.2/2.3.17/2.2.21)
• DDS:
  • Don't set "texturetype" metadata, it should always have been only "textureformat". Also, add unit testing of DDS to the testsuite. #3200 (2.4.0/2.3.10)
  • IOProxy support. #3217 (2.4.0)
  • Add support for BC4-BC7 compression methods. #3459 (2.4.2)
  • Speed up reading of uncompressed DDS images (by about 3x). #3463
  • Better handling of cube maps with MIPmap levels. #3467 (2.4.0)
  • For 2-channel DDS files, label them as Y,A if the flags indicate luminance and/or alpha, otherwise label them as R,G. #3530 (2.4.2.2)
  • Do not set "oiio:BitsPerSample" for cases where the dds.fmt.bpp field is not assumed to be valid. MS docs say it's valid only if the flags field indicates RGB, LUMINANCE, or YUV types. #3530 (2.4.2.2)
• FFMpeg
  • Now uses case-insensitive tests on file extensions, so does not get confused on Windows with all-caps filenames. #3364 (2.4.1.0/2.3.14)
  • Take care against possible double-free of allocated memory crash upon destruction. #3376 (2.4.1.0/2.3.14)
• GIF
  • IOProxy support. #3181 (2.4.0/2.3.10)
• HDR:
  • IOProxy support. #3218 (2.4.0)
• HEIF:
  • Handle images with unassociated alpha. #3146 (2.4.0/2.3.9)
• JPEG:
  • IOProxy support. #3182 (2.4.0/2.3.10)
  • Better handling of PixelAspectRatio. #3366 (2.4.1.0)
  • Fix multithreaded race condition in read_native_scanline. #3495 (2.4.2.2)
  • Fix bug in XRes,YRes aspect ratio logic. #3500 (2.4.2.2)
  • When asked to output 2-channel images (which JPEG doesn't support), use the channel names to decide whether to drop the second channel (if it seems to be a luminance/alpha image) or add a third black channel (other cases). #3531 (2.4.2.2)
• JPEG2000:
  • Enable multithreading for decoding (if using OpenJPEG >= 2.2) and encoding (if using OpenJPEG >= 2.4). This speeds up JPEG-2000 I/O by 3-4x. #2225 (2.3.11/2.4.0)
  • IOProxy support. #3226 (2.4.0)
  • Better detection and error reporting of failure to open the file. #3440 (2.4.2)
• OpenEXR:
  • When building against OpenEXR 3.1+ and when the global OIIO attribute "openexr:core" is set to nonzero, do more efficient multithreaded reading of OpenEXR files. #3107 (2.4.0/2.3.9.1)
  • Fix excessive memory usage when saving EXR files with many channels. #3176 (2.4.0/2.3.10)
  • When building against OpenEXR >= 3.1.3, our OpenEXR output now supports specifying the zip compression level (for example, by passing the "compression" metadata as "zip:4"). Also note than when using OpenEXR >= 3.1.3, the default zip compression has been changed from 6 to 4, which writes compressed files significantly (tens of percent) faster, but only increases compressed file size by 1-2%. #3157 (2.4.0/2.3.10) Fixes in #3387 (2.4.1.1)
  • Fix writing deep exrs when buffer datatype doesn't match the file. #3369 (2.4.1.0/2.3.14)
• PNG:
  • Assume sRGB color space as default when no color space attribute is in the file. #3321 (2.4.0.2/2.3.13)
  • Improve error detection and propagation for corrupt/broken files. #3442 (2.4.2)
  • Improve error detection and messages when writing PNG files, for various kinds of errors involving metadata. #3535 (2.4.2.2)
• PPM:
  • Mark all PPM files as Rec709 color space, which they are by specification. #3321 (2.4.0.2/2.3.13)
• PSD:
  • IOProxy support. #3220 (2.4.0)
  • Better error messages for corrupted files and other failures. #3469 (2.4.0)
• RAW:
  • When using libraw 0.21+, now support new color space names "DCE-P3", "Rec2020", and "sRGB-linear", and "ProPhoto-linear". Fix incorrect gamma values for "ProPhoto". #3123 #3153 (2.4.0/2.3.9.1)
• RLA:
  • Better guards against malformed input. #3163 (2.4.0/2.3.10)
• Targa:
  • Improved error detection for read errors and corrupted files. #3120 (2.4.0/2.3.9.1) #3162 (2.4.0/2.3.10)
  • Fixed bug when reading x-flipped images. #3162 (2.4.0/2.3.10)
  • IOProxy support. #3221 (2.4.0)
  • Better interpretation of TGA 1.0 files with alpha that is zero everywhere. Be more consistent with Targa attributes all being called "targa:foo". Add "targa:version" to reveal whether the file was TGA 1.0 or 2.0 version of the format. #3279 (2.4.0.1/2.3.12)
  • Fix parsing of TGA 2.0 extension area when the software name was missing form the header. #3323 (2.4.0.2/2.3.13)
  • Fix reading of tiny 1x1 2-bpp Targa 1.0 images. #3433 (2.3.17/2.2.21)
• Socket imageio plugin has been removed entirely, it never was completed or did anything useful. #3527 (2.3.2.2)
• TIFF:
  • IOProxy is now supported for TIFF output. #3075 (2.4.0/2.3.8)
  • Honor zip compression quality request when writing TIFF. #3110 (2.4.0/2.3.11)
  • Automatically switch to "bigtiff" format for really big (> 4GB) images. #3158 (2.4.0)
  • Support for palette images with 16 bit palette indices. #3262 (2.4.0/2.3.12)
  • Gracefully handle missing ExtraSamples tag. #3287 (2.4.0.1/2.3.12)
  • New output configuration hint: "tiff:write_extrasamples" (default: 1), if set to 0, will cause the TIFF output to NOT include the required EXTRASAMPLES tag in the header. This is not recommended, but fixes a specific problem in some circumstances where PhotoShop misbehaves when the extrasamples tag is present. #3289 (2.4.0.1)
  • No longer write IPTC blocks to the TIFF header by default, it caused trouble and was sometimes corrupted. You can force it to write an IPTC block by using the output open configuration hint "tiff:write_iptc" set to nonzero. #3302 (2.4.0.1)
  • Fix read problems with TIFF files with non-zero y offset. #3419 (2.3.17/2.4.2)
  • Fixed some longstanding issues with IPTC data in the headers. #3465 (2.4.0)
  • Protect against crashes with certain empty string attributes. #3491 (2.4.2.1)
• WebP:
  • Fix previous failure to properly set the "oiio:LoopCount" metadata when reading animated webp images. #3183 (2.4.0/2.3.10)
  • IOProxy support. #3224 (2.4.0)
• Better catching of exceptions thrown by OCIO 1.x if it encounters 2.0 config files. #3089 (2.4.0/2.3.9)
• Improved internal logic and error reporting of missing OCIO configs. #3092 #3095
• Improved finding of fonts (by IBA::render_text and oiiotool --text). It now honors environment variable $OPENIMAGEIO_FONTS and global OIIO attribute "font_searchpath" to list directories to be searched when fonts are needed. #3096 (2.4.0/2.3.8)
• Fix crash that could happen with invalidly numbered UDIM files. #3116 (2.4.0/2.3.9)
• Fix possible bad data alignment and SIMD assumptions inside TextureSystems internals. #3145 (2.4.0/2.3.9)
• Update internal stb_printf implementation (avoids some sanitizer alerts). #3160 (2.4.0/2.3.10)
• Replace the few remaining instances of sscanf in the codebase with Strutil utilities that are guaranteed to be locale-independent. #3178 (2.4.0)
• Security: New global OIIO attributes "limits:channels" (default: 1024) and "limits:imagesize_MB" (default: 32768, or 32 GB) are intended to reject input files that exceed these limits, on the assumption that they are either corrupt or maliciously constructed, and would, if read, lead to absurd allocations, crashes, or other mayhem. Apps may lower or raise these limits if they know that a legitimate input image exceeds these limits. Currently, only the TIFF reader checks these limits, but others will be modified to honor the limits over time. #3230 (2.3.11/2.4.0)
• Fix integer overflow warnings. #3329 (2.4.1.0)
• Improved behavior when opening a file whose format doesn't correctly match its extension: try common formats first, rather than alphabetically; and improve error messages. #3400 (2.4.2)
• The maximum number of threads you can set with option "oiio:threads" has been increased from 256 to 512. #3484 (2.4.2.1)
• Make access to the internal imageio_mutex not be recursive. #3489 (2.4.2.2)
• Various protections against string metadata found in file that has zero length. #3493 (2.4.2.2)
• Fix possible null pointer dereference in inventory_udim. #3498 (2.4.2.2)
• oiiotool, maketx, iinfo, igrep, and iv now all take a --version command line argument, which just prints the OIIO version and exits. #3534

Developer goodies / internals:

• benchmark.h:
  • Alter the declaration of DoNotOptimize() so that it doesn't have compilation problems on some platforms. #3444 (2.4.2/2.3.17)
• filesystem.h:
  • A new version of searchpath_split returns the vector of strings rather than needing to be passed a reference. #3154 (2.4.0/2.3.10)
  • New write_binary_file() utility function. #3199 (2.4.0/2.3.10)
  • searchpath_split() fixes to better handle empty paths. #3306 (2.4.0.1)
• fmath.h:
  • Added round_down_to_multiple(). Also, more correctly handle round_to_multiple() results when the value is < 0. #3104
  • Add round_down_to_multiple() and improve round_to_multiple() to correctly handle cases where the value is less than 0. #3104 (2.4.0/2.3.8)
  • Make bit_cast specialization take refs, like the template. This fixes warnings for some compilers. #3213 (2.4.0/2.3.10.1)
• imageio.h:
  • ImageInput and ImageOutput have many new helper methods (protected, meant for II and IO subclass implementations to use, not users of these classes) for helping to implement IOProxy support in format readers and writers. #3203 #3222 (2.4.0)
• Imath.h:
  • In addition to including the right Imath headers for the version that OIIO is built with, this defines custom formatters for the Imath types for use with fmt::format/print or Strutil::format/print. #3367 (2.4.1.0)
• oiioversion.h
  • OIIO_MAKE_VERSION_STRING and OIIO_VERSION_STRING now print all 4 version parts. #3368 (2.4.1.0)
• parallel.h
  • Refactoring of the entry points (back compatible for API), and add support for using TBB for the thread pool (which seems slightly faster than our internal thread pool). By default it still uses the internal pool, but if OIIO::attribute("use_tbb") is set to nonzero, it will use the TBB thread pool if built against TBB. #3473 (2.4.2.2) #3566 (2.4.4.0)
• paramlist.h
  • Various internal fixes that reduce the amount of ustring construction that happens when constructing ParamValue and ParamList, and making certain ImageSpec::attribute() calls. #3342 (2.4.1.0)
• simd.h:
  • Better guards to make it safe to include from Cuda. #3291 #3292 (2.4.0.1/2.3.12)
  • Fix compiler warnings related to discrepancies between template declaration and redeclaration in simd.h. #3350 (2.4.1.0/2.3.14)
  • The vector types all now have a size() method giving its length. #3367 (2.4.1.0)
  • Defines custom formatters for the vector and matrix types, for use with fmt::format/print or Strutil::format/print. #3367 (2.4.1.0)
• string_view.h
  • Auto-conversion between our string_view, std::string_view (when available), and fmt::string_view. #3337 (2.4.1.0)
  • OIIO::string_view is now fully templated, to match std::string_view. #3344 (2.4.1.0)
• strutil.h:
  • New utility functions: parse_values(), scan_values(), scan_datetime() #3173 #3177 (2.4.0/2.3.10), edit_distance() #3229 (2.4.0/2.3.11)
  • The utf8_to_utf16() and ut16_to_utf8() utilities are now exposed on all platforms, not just windows (and their internals have been modernized). #3307 (2.4.0.1)
  • Strutil::isspace() is a safe alternative to C isspace(), that works even for signed characters. #3310 (2.4.1.0)
  • Strutil::print() now is buffered (and much more efficient, and directly wraps fmt::print). A new Strutil::sync::print() is a version that does a flush after every call. #3348 (2.4.1.0)
  • get_rest_arguments() fixes conflict between RESTful and Windows long path notations. #3372 (2.4.1.0/2.3.14)
  • Dramatically speed up (50-100x) Strutil iequals, iless, starts_with, istarts_with, ends_with, iends_with. #3388 (2.4.1.1)
  • New safe_strcat is a buffer-length-aware safe replcement for strcat. #3471 (2.4.0/2.3.18)
  • Strutil::debug() is the new OIIO::debug(), moving it from libOpenImageIO to libOpenImageIO_Util. #3486 (2.4.2.1)
  • New Strutil::safe_strlen() is a portable safe strlen replacement. #3501 (2.4.2.2)
• sysutil.h:
  • The Term class now recognizes a wider set of terminal emulators as supporting color output. #3185 (2.4.0)
• timer.h:
  • Timer::add_seconds() and Timer::add_ticks() allows add/subtract directly to a timer's elapsed value. #3070 (2.4.0/2.3.8)
  • For Linux, switch from using gettimeofday to clock_gettime, for potentially higher resolution. #3443 (2.4.2)
• typedesc.h:
  • Add Cuda host/device decorations to TypeDesc methods to make them GPU friendly. #3188 (2.4.0/2.3.10)
  • TypeDesc constructor from a string now accepts "box2f" and "box3f" as synonyms for "box2" and "box3", respectively. #3183 (2.4.0/2.3.10)
• type_traits.h:
  • This new header contains a variety of type traits used by other OIIO headers. They aren't really part of the public API, but they are sometimes used by public headers. #3367 (2.4.1.0)
• unittest.h:
  • Changes OIIO_CHECK_SIMD_EQUAL_THRESH macro to compare <= eps instead of <. #3333 (2.4.0.3)
• unordered_map_concurrent.h: Fix bug in erase() method. #3485 (2.4.2.2)
• ustring.h:
  • New static method from_hash() creates a ustring from the known hash value. #3397 (2.4.2)
  • New ustringhash class is just like a ustring, except that the "local" representation is the hash, rather than the unique string pointer. #3436 (2.4.2)
• vecparam.h:
  • New V3fParam, M33fParam, and M44fParam (defined in vecparam.h) are used just for parameter passing in public APIs, instead of Imath::V3f, M33f, or M44f, in order to more fully hide Imath types from our public interfaces. These are only parameter-passing classes, and are not useful as vector or matrix classes in their own right. But they seamlessly cast to and from other vector- and matrix-like classes. #3330 (2.4.1.0)
• More internals conversion to use the new fmt style for string formatting, console output, error messages, and warnings: oiiotool internals #3240 (2.4.0); TS/IC stats output #3374 (2.4.1.0); misc #3777 (2.4.1.0); testshade #3415 (2.4.2)
• Internals are working toward removing all uses of string_view::c_str(), since that isn't part of C++17 std::string_view. #3315 (2.4.0.1)
• New testtex options: --minthreads sets the minimum numer of threads that will be used for thread wedges, --lowtrials is an optional maximum number of trials just for the 1 or 2 thread cse. #3418 (2.4.2)
• Internals: internal classes with vertual methods now mark all their overridden destructors correctly as override. #3481 (2.4.2.1) #3488 #3511 (2.4.2.2)

Build/test system improvements and platform ports:

• CMake build system and scripts:
  • Remove the old FindOpenImageIO.cmake module; downstream clients should instead use our exported configs. #3098 (2.4.0/2.3.8)
  • Fix over-use of targets when we should have been using variables. #3108 (2.4.0/2.3.9)
  • CMake variable -DENABLE_INSTALL_testtex=1 causes testtex to be installed as an application. #3111 (2.4.0)
  • Make OpenImageIO_SUPPORTED_RELEASE into a CMake cache variable so it can be overridden at build time. #3142 (2.4.0)
  • New build option -DTIME_COMMANDS=ON will print time to compile each module (for investigating build performance; only useful when building with CMAKE_BUILD_PARALLEL_LEVEL=1). #3194 (2.4.0/2.3.10)
  • PROJECT_VERSION_RELEASE_TYPE is now a cache variable that can be overridden at build time. #3197 (2.4.0/2.3.10)
  • Set and use the variable PROJECT_IS_TOP_LEVEL to know if OIIO is a top level project or a subproject. #3197 (2.4.0/2.3.10)
  • Restore code that finds Jasper when using statically-linked libraw. #3210 (2.4.0/2.3.10.1)
  • Gracefully handle failing to find git for test data download. #3212 (2.4.0/2.3.10.1)
  • Make sure to properly use the tbb target if it exists. #3214 (2.4.0/2.3.10.1)
  • Use a project-specific "OpenImageIO_CI" for whether we're running in CI, rather than the confusingly generic "CI" #3211 (2.4.0/2.3.11)
  • If CMake variable BUILD_TESTING is OFF, don't do any automatic downloading of missing test data. #3227 (2.3.11/2.4.0)
  • Fixes to FindOpenColorIO.cmake module, now it prefers an OCIO exported cmake config (for OCIO 2.1+) unless OPENCOLORIO_NO_CONFIG=ON is set. #3278 (2.4.0.1/2.3.12)
  • Fix problems with FindOpenEXR build script for Windows. #3281 (2.4.0.1/2.3.12)
  • New CMake cache variable DOWNSTREAM_CXX_STANDARD specifies which C++ standard is the minimum for downstream projects (currently 14), which may be less than the CMAKE_CXX_STANDARD that specifies which C++ standard we are using to build OIIO itself. #3288 (2.4.0.1)
  • The exported cmake configs now use relative paths so they are relocatable. #3302 (2.4.0.1)
  • CMake variable OPENIMAGEIO_CONFIG_DO_NOT_FIND_IMATH, if set to ON, will make our generated config file not do a find_dependency(Imath). (Use with caution.) #3335 (2.4.0.3)
  • Can now do unity/jumbo builds. This isn't helpful when building with many cores/threads, but in thread-limited situtations (such as CI), it can speed up builds a lot to use -DCMAKE_UNITY_BUILD=ON. #3381 #3389 #3392 #3393 #3398 #3402 (2.4.2.0)
  • Do not auto-download test images by default. To auto download test images, build with -DOIIO_DOWNLOAD_MISSING_TESTDATA=ON. #3409 (2.4.0)
  • Allow using the Makefile wrapper on arm64 systems. #3456 (2.4.2)
  • The export OpenImageIOConfig.cmake fixes OpenImageIO_INCLUDE_DIR to work correctly on Debian systems where there are multiple filesystem components to the path. #3487 (2.4.2.1)
  • On MacOS, do not force MACOS_RPATH on. #3523 (2.4.2.2)
  • Improvements to the generated cmake config files when building static libraries. #3552 #3557 (2.4.4.0)
• Dependency version support:
  • When using C++17, use std::gcd instead of boost. #3076 (2.4.0)
  • When using C++17, use inline constexpr instead of certain statics. #3119 (2.4.0)
  • Fixes to work with the libraw 202110 snapshot. #3143 (2.4.0/2.3.9.1)
  • Fix occasional build breaks related to OpenCV headers. #3135 (2.4.0/2.3.9)
  • The internals of Filesystem::searchpath_split have been reimplemented in such a way as to no longer need boost.tokenzer. #3154 (2.4.0/2.3.10)
  • Deal with the fact that OpenColorIO has changed its default branch name to "main". #3169 (2.4.0/2.3.10/2.2.20)
  • pybind11 v2.9.0 incorporated into our testing and CI. #3248
  • Fix clang10 compile warnings. #3272 (2.4.0.1/2.3.12)
  • Support for ffmpeg 5.0. #3282 (2.4.0.2/2.3.13)
  • Support for fmtlib 9.0.0. #3327 (2.4.0.2/2.3.13) #3466 (2.4.2/2.3.18)
  • build_opencolorio.bash helper script bumped its default build of OpenColorIO to 2.1.2. #3475 (2.4.2.1)
  • When building with C++17 or higher, Boost.filesystem is no longer needed or used. #3472 #3477 (2.4.2.1)
  • Upgrade the internal fallback implemention of PugiXML to the latest version. #3494 (2.4.2.2)
  • Fixes for ffmpeg 5.1 detection. #3516 (2.3.19.0/2.4.2.2)
  • Support for gcc 12.1. #3480 (2.4.2.1) #3551 (2.4.4.0)
  • Support building with clang 15.0. #3563 (2.4.4.0)
• Testing and Continuous integration (CI) systems:
  • Properly test against all the versions of VFX Platform 2022. #3074 (2.4.0)
  • The helper script build_libtiff.bash now allows you to override the build type (by setting LIBTIFF_BUILD_TYPE) and also bumps the default libtiff that it downloads and builds from 4.1.0 to 4.3.0. #3161 (2.4.0)
  • New tests on MacOS 11 #3193 (2.4.0/2.3.10) and MacOS 12, remove test on MacOS 10.15 (GitHub Actions is imminently removing MacOS 10.15). #3528 (2.3.19.0/2.4.2.2)
  • Add a DDS test (we never had one before). #3200 (2.4.0/2.3.10)
  • imageinout_test now has options to make it easy to unit test just one named format, as well as to preserve the temp files for inspection. #3201 (2.4.0/2.3.10)
  • Add an HDR test (we never had one before). #3218 (2.4.0)
  • Fix bugs in the build_opencolorio.bash script, did not correctly handle installation into custom directories. #3278 (2.4.0.1/2.3.12)
  • Failed build artifact storage is revised to save more cmake-related artifacts to help debugging. #3311 (2.4.0.1)
  • Now doing CI builds for Intel icc and icx compilers. #3355 #3363 (2.4.1.0/2.3.13) #3407 (2.4.0)
  • Overhaul of ci.yml file to be more clear and compact by using GHA "strategy" feature. #3356 #3365 (2.4.1.0/2.3.13)
  • Removed CI for windows-2016 GHA instance which will soon be removed. #3370 (2.4.1.0)
  • Test against clang 14. #3404
  • Various guards against supply chain attacks durig CI. #3454 (2.4.2)
  • Test against pybind11 v2.10. #3478 (2.4.2.1)
  • Run SonarCloud nightly for static analysis and coverage analysis. #3505 (2.4.2.2)
• Platform support:
  • Fix when building with Clang on big-endian architectures. #3133 (2.4.0/2.3.9)
  • Improvements to NetBSD and OpenBSD support. #3137. (2.4.0/2.3.9)
  • Fixes for MSVS compile. #3168 (2.4.0/2.3.10)
  • Fix problems on Windows with MSVC for Debug builds, where crashes were occurring inside isspace() calls. #3310
  • Improved simd.h support for armv7 and aarch32. #3361 (2.4.1.0/2.3.14)
  • Suppress MacOS wasnings about OpenGL deprecation. #3380 (2.4.1.0/2.3.14)
  • Fix MSVS/Windows errors. #3382 (2.4.1.1)
  • Fix cross-compiling on Android failing due to -latomic check. #3560 (2.4.4.0)
  • Fix building on iOS. #3562 (2.4.4.0)

Notable documentation changes:

• Add an oiiotool example of putting a border around an image. #3138 (2.4.0/2.3.9)
• Fix explanation of ImageCache "failure_retries" attribute. #3147 (2.4.0/2.3.9)
• Improved maketx argument explanations.
• Clean up intra-document section references. #3238 (2.3.11/2.4.0)
• New explanations about input and output configuration hints. #3238 (2.3.11/2.4.0)
• More code examples in both C++ and Python (especially for the ImageInput, ImageOutput, and ImageBufAlgo chapters). #3238 #3244 #3250 (2.3.11/2.4.0) #3263 (2.3.12/2.4.0)
• Pretty much anyplace where a parameter that represents a filename, and it is supporting UTF-8 encoding of Unicode filenames, the docs for that function explicitly say that the string is assumed to be UTF-8. #3312 (2.4.0.1)
• Fix many typos in docs. #3492 (2.4.2.2)

Release 2.3.20 (1 Oct 2022) -- compared to 2.3.19

• Fixes to compile with gcc 12. #3551
• Fixes to compile with clang 15. #3563
• PNG: better error handling when errors are encountered while writing. #3535

Release 2.3.19 (1 Sep 2022) -- compared to 2.3.18

• idiff: --allowfailures allows the specified number of pixels to differ by any amount, and still consider the images to compare successfully. #3455
• idiff: --failrelative and --warnrelative allows the failure and warning threshold to use a symmetric mean relative error (rather than the absolute error implied by the existing --fail and --warn arguments). #3508
• Build: Fixes for ffmpeg 5.1 detection. #3516
• Build: suppress incorrect warnings for gcc 12. #3524
• CI: New test on MacOS 12, remove test on MacOS 10.15 (GitHub Actions is imminently removing MacOS 10.15). #3528
• oiiotool, maketx, iinfo, igrep, and iv now all take a --version command line argument, which just prints the OIIO version and exits. #3534
• OIIO::getattribute("version") now retrieves the version string. #3534
• Developer goodies: ArgParse::add_version(str) tells ArgParse the version string, which will automatically add an option --version. #3534

Release 2.3.18 (1 Aug 2022) -- compared to 2.3.17

• Windows: Allow loading of dlls from PATH on Python 3.8+. #3470
• JPEG: Fix a race condition in read_native_scanline. #3495
• JPEG: Fix aspect ratio logic. #3500
• Bug fix: incorrect assignment of oiio_missingcolor attribute. #3497
• Bug fix: possible null pointer dereference in inventory_udim(). #3498
• Bug fix: print_info_subimage botched condition. #3499
• CI: Test against fmt 9.0.0. #3466
• CI: Test against pybind11 v2.10. #3478
• Strutil: safe_strcat() #3471 and safe_strlen() #3501
• Change build_opencolorio.bash to default to OCIO 2.1.2. #3475

Release 2.3.17 (1 Jul 2022) -- compared to 2.3.16

• TIFF: fix read problems with TIFF files with non-zero y offset. #3419
• Targa: Fix reading of tiny 1x1 2-bpp Targa 1.0 images. #3433 (2.3.17/2.2.21)
• BMP: better detection of corrupted files with nonsensical image dimensions or total size. #3434 (2.3.17/2.2.21)
• BMP: protect against corrupted files that have palette indices out of bound. #3435 (2.3.17/2.2.21)
• TextureSystem: Fix typo that prevented "max_tile_channels" attribute from being set or retrieved. (2.3.17)
• ustring.h: ustring has added a from_hash() static method #3397, and a ustringhash helper class #3436. (2.3.17/2.2.21)
• benchmark.h: Alter the declaration of DoNotOptimize() so that it doesn't have compilation problems on some platforms. #3444 (2.3.17)
• Fix crash when ioproxy is passed to an image writer that doesn't support it. #3453 (2.3.17)
• Fix the "Makefile" wrapper to correctly recognize arm64 ("Apple silicon"). #3456 (2.3.17)

Release 2.3.16 (1 Jun 2022) -- compared to 2.3.15

• Support for Intel llvm-based compiler 2022.1.0. #3407
• Internals: custom fmt formatters for vector types. #3367
• Fix compiler breaks when using some changes in fmtlib master (not yet released). #3416
• UDIM textures have been sped up by 5-8%. #3417

Release 2.3.15 (1 May 2022) -- compared to 2.3.14

• JPEG: Better handling of PixelAspectRatio. #3366
• OpenEXR: Fix DWAA compression default level. #3387
• Perf: Huge speed-up of case-insensitive string comparisons (Strutil iequals, iless, starts_with, istarts_with, ends_with, iends_with), which also speeds up searches for attributes by name in ImageSpec and ParamValueList. #3388
• New ImageBufAlgo::st_warp() (and oiiotool --st_warp) perform warping of an image where a second image gives the (s,t) coordinates to look up from at every pixel. #3379
• Python: Add ImageSpec and ParamValueList method get_bytes_attribute(), which is like get_string_attribute(), but returns the string as a Python bytes object. In Python 3, strings are UTF-8, so this can be useful if you know that a string attribute might contain non-UTF8 data. #3396

Release 2.3.14 (1 Apr 2022) -- compared to 2.3.13

• Add support for UDIM pattern <uvtile> (used by Clarisse & V-Ray). #3358
• BMP: Support for additional (not exactly fully documented) varieties used by some Adobe apps. #3375
• Python: support uint8 array attributes in and out. This enables the proper Python access to "ICCProfile" metadata. #3378
• Improved precision in IBA::computePixelStats(). #3353
• ffmpeg reader not uses case-insensitive tests on file extensions. #3364
• Fix writing deep exrs when buffer datatype doesn't match the file. #3369
• Fix conflict between RESTful and Windows long path notations. #3372
• ffmpeg reader: take care against possible double-free of allocated memory crash upon destruction. #3376
• simd.h fixes for armv7 and aarch32. #3361
• Fix compiler warnings related to discrepancies between template declaration and redeclaration in simd.h and benchmark.h. #3350
• Suppress MacOS warnings about OpenGL depreation. #3380
• Now doing CI builds for Intel icc and icx compilers. #3355 #3363
• CI: Overhaul of yml file to be more clear and compact by using GHA "strategy" feature. #3356 #3365

Release 2.3.13 (1 Mar 2022) -- compared to 2.3.12

• Filesystm::searchpath_split better handling of empty paths. #3306
• New Strutil::isspace() is an isspace replacement that is safe for char values that are < 0. #3310
• Expose the Strutil::utf8_to_utf16() and utf16_to_utf8() utilities on non-Windows platforms (and also modernize their internals). #3307
• For the most important ImageInput, ImageOutput, and ImageBuf methods that take a filename, add new flavors that can accept a wstring as the filename. #3312 #3318
• PPM: properly report color space as Rec709 (as dictated by PPM spec). #3321
• PNG: more robust reporting of color space as sRGB in the absence of header fields contradicting this. #3321
• strutil.h: Split the including of fmt.h and some related logic into a separate detail/fmt.h. This is still included by strutil.h, so users should not notice any change. #3327
• Targa: Fix parsing of TGA 2.0 extension area. #3323
• Support building against FFmpeg 5.0. #3282
• oiiotool --pixelaspect : fix setting of "PixelAspectRatio", "XResolution", and "YResolution" attributes in the output file (were not set properly before). #3340

Release 2.3.12 (1 Feb 2022) -- compared to 2.3.11

• oiiotool: Don't give spurious warnings about no output when the --colorcount or --rangecheck commands are used. #3262
• oiiotool --pattern checker fixed behavior so that if only the checker width was specified but not the height, height will be equal to width. #3255
• oiiotool --point lets you set individual pixels. #3256
• Python: A new ImageBuf constructor was added that takes only a NumPy ndarray, and deduces the resolution, channels, and format (pixel data type) from the shape of the array. #3246
• Python: Implement ROI.copy(). #3253
• Python: ImageSpec and ParamValueList now support 'key' in spec, del spec['key'], and spec.get('key', defaultval) to more fully emulate Python dict syntax for manipulating metadata. #3252 (2.3.12/2.4.0)
• Python bug fix: fix clamp() when the min or max are just a float. Now it uses that one value for all channels, instead of using it only for the first channel. #3265
• ImageSpec gained an additional constructor that takes a string representation of the pixel data type (where it used to insist on a TypeDesc), such as ImageSpec(640, 480, 3, "uint8"). This is especially helpful for new/casual users, or when you want code to be maximally readable. #3245
• Imagepec::getattribute() new query token "format" can retrieve the pixel data type. #3247
• IBA::make_texture(): ensure that "maketx:ignore_unassoc" is honored. #3269
• Support an additional UDIM pattern <UVTILE>, which is specified by MaterialX. #3280
• TIFF: support 16-bit palette images. #3260
• TIFF: Gracefully handle missing ExtraSamples tag. #3287
• Targa: Better interpretation of TGA 1.0 files with alpha that is zero everywhere. Be more consistent with Targa attributes all being called "targa:foo". Add "targa:version" to reveal whether the file was TGA 1.0 or 2.0 version of the format. #3279
• simd.h: Better guards to make it safe to include from Cuda. #3291 #3292
• Fix bugs in the build_opencolorio.bash script, did not correctly handle installation into custom directories. #3278
• Fixes to FindOpenColorIO.cmake module, now it prefers an OCIO exported cmake config (for OCIO 2.1+) unless OPENCOLORIO_NO_CONFIG=ON is set. #3278
• Docs: The ImageBufAlgo chapter now has examples for C++, Python, and oiiotool for almost every operation. #3263

Release 2.3.11 (1 Jan 2022) -- compared to 2.3.10

• JPEG2000: enable multithreading for decoding (if using OpenJPEG >= 2.2) and encoding (if using OpenJPEG >= 2.4). This speeds up JPEG-2000 I/O by 3-4x. #2225
• TIFF: automatically switch to "bigtiff" format for >4GB images. #3158
• Security: New global OIIO attributes "limits:channels" (default: 1024) and "limits:imagesize_MB" (default: 32768, or 32 GB) are intended to reject input files that exceed these limits, on the assumption that they are either corrupt or maliciously constructed, and would, if read, lead to absurd allocations, crashes, or other mayhem. Apps may lower or raise these limits if they know that a legitimate input image exceeds these limits. Currently, only the TIFF reader checks these limits, but others will be modified to honor the limits over time. #3230
• TextureSystem: enhance safety/correctness for untiled images that exceed 2GB size (there was an integer overflow problem in computing offsets within tiles). #3232
• Cleanup: Get rid of an obsolete header c-imageio.h that was experimental and the functions declared therein were not implemented in this release. #3237
• Build: rely on env variable "OpenImageIO_CI" to tell us if we are running in a CI environment, not the more generic "CI" which could be set for other reasons in some environments. #3211
• Build: Improvements in how we find OpenVDB. #3216
• Build: If CMake variable BUILD_TESTING is OFF, don't do any automatic downloading of missing test data. #3227
• Dev: Add Strutil::edit_distance(). #3229
• Docs: Clean up intra-document section references, new explanations about input and output configuration hints, more code examples in both C++ and Python (especially for the ImageInput and ImageOutput chapters). #3238 #3244

Release 2.3.10.1 (7 Dec 2021) -- compared to 2.3.10.0

• Build: restore code that finds Jasper when using statically-linked libraw. #3210
• Build/test: Gracefully handle failing to find git for test data download. #3212
• fmath.h: bit_cast specialization should take refs, like the template. This made warnings for some compilers. #3213
• Build: make sure to properly use the tbb target if it exists. #3214

Release 2.3.10 (1 Dec 2021) -- compared to 2.3.9

New (non-compatibility-breaking) features:

• TextureSystem: add feature for stochastic mipmap interpolation. This adds new interpolation modes "StochasticTrilinear" and "StochasticAniso", which in conjunction with the "rnd" field in TextureOpt, will stochastically choose between bracketing MIPmap levels rather than interpolating them. This reduces texture lookup cost by up to 40%, but it's only useful in the context of a renderer that uses many samples per pixel. #3127
• maketx/make_texture() now supports options to store Gaussian forward and inverse transform lookup tables in image metadata (must be OpenEXR textures for this to work) to aid writing shaders that use histogram-preserving blending of texture tiling. This is controlled by new maketx arguments --cdf, --cdfsigma, --sdfbits, or for IBA::make_texture() by using hints maketx:cdf, maketx:cdfsigma, and maketx:cdfbits. #3159 #3206
• oiitool --oiioattrib can set "global" OIIO control attributes for an oiiotool run (equivalent of calling OIIO::attribute()). #3171
• oiiotool --repremult exposes the previously existing IBA::repremult(). The guidance here is that --premult should be used for one-time conversion of "unassociated alpha/unpremultiplied color" to associated/premultiplied, but when you are starting with a premultiplied image and have a sequence of unpremultiply, doing some adjustment in unpremultiplied space, then re-premultiplying, it's --repremult you want as the last step, because it preserves alpha = 0, color > 0 data without crushing it to black. #3192
• oiiotool --saturate and IBA::saturate() can adjust saturation level of a color image. #3190
• oiiotool --maxchan and --minchan, and IBA::maxchan() and minchan() turn an N-channel image into a 1-channel images that for each pixel, contains the maximum value in any channel of the original for that pixel. #3198
• When building against OpenEXR >= 3.1.3, our OpenEXR output now supports specifying the zip compression level (for example, by passing the "compression" metadata as "zip:4"). Also note than when using OpenEXR >= 3.1.3, the default zip compression has been changed from 6 to 4, which writes compressed files significantly (tens of percent) faster, but only increases compressed file size by 1-2%. #3157
• Improved image dithering facilities: When dithering is chosen, it now happens any time you reduce >8 bits to <= 8 bits (not just when converting from float or half); change the dither pattern from hashed to blue noise, which looks MUCH better (beware slightly changed appearance); IBA::noise() and oiiotool --noise now take "blue" as a noise name, giving a blue noise pattern; IBA::bluenoise_image() returns a reference to a stored periodic blue noise image; oiiotool -d now lets you ask for "uint6", "uint4", "uint2", and "uint1" bit depths, for formats that support them. #3141
• New global OIIO attribute "try_all_readers" can be set to 0 if you want to override the default behavior and specifically NOT try any format readers that don't match the file extension of an input image (usually, it will try that one first, but it if fails to open the file, all known file readers will be tried in case the file is just misnamed, but sometimes you don't want it to do that). #3172
• Raise the default ImageCache default tile cache from 256MB to 1GB. This should improve performance for some operations involving large images or images with many channels. #3180
• IOProxy support has been added to JPEG output (already was supported for JPEG input) and for GIF input and output. #3181 #3182

Bug fixes:

• Fix oiiotool --invert to avoid losing the alpha channel values. #3191
• Fix excessive memory usage when saving EXR files with many channels. #3176
• WebP: Fix previous failure to properly set the "oiio:LoopCount" metadata for animated webp images. #3183
• Targa: Better detection/safety when reading corrupted files, and fixed bug when reading x-flipped images. #3162
• RLA: better guards against malformed input. #3163
• Fix oiiotool bug when autocropping output images when the entire pixel data window is in the negative coordinate region. #3164
• oiiotool improved detection of file reading failures. #3165
• DDS: Don't set "texturetype" metadata, it should always have been only "textureformat". Also, add unit testing of DDS to the testsuite. #3200
• When textures are created with the "monochrome-detect" feature enabled, which turns RGB textures where all channels are always equal into true single channel greyscale, the single channel that results is now correctly named "Y" instead of leaving it as "R" (it's not red, it's luminance). #3205

Build fixes and developer goodies:

• Update internal stb_printf implementation (avoids some sanitizer alerts). #3160
• Fixes for MSVS compile. #3168
• Add Cuda host/device decorations to TypeDesc methods to make them GPU friendly. #3188
• TypeDesc: The constructor from a string now accepts "box2f" and "box3f" as synonyms for "box2" and "box3", respectively. #3183
• New Strutil::parse_values, scan_values, scan_datetime, parse_line. #3173 #3177
• New Filesystem::write_binary_file() utility function. #3199
• New build option -DTIME_COMMANDS=ON will print time to compile each module (for investigating build performance; only useful when building with CMAKE_BUILD_PARALLEL_LEVEL=1). #3194

Release 2.3.9.1 (1 Nov 2021) -- compared to 2.3.8

• OpenEXR: When building against OpenEXR 3.1+ and when the global OIIO attribute "openexr:core" is set to nonzero, do more efficient multithreaded reading of OpenEXR files. #3107
• oiiotool --dumpdata:C=name causes the dumped image data to be formatted with the syntax of a C array. #3136
• oiiotool: Allow quotes in command modifiers. #3112
• jpeg input: remove stray debugging output to console. #3134
• HEIF: Handle images with unassociated alpha. #3146
• Targa: improved error detection for read errors and corrupted files. #3120
• raw: When using libraw 0.21+, now support new color space names "DCE-P3", "Rec2020", and "sRGB-linear", and "ProPhoto-linear". Fix incorrect gamma values for "ProPhoto". #3123 #3153 Fixes to work with the libraw 202110 snapshot. #3143
• TIFF: honor zip compression quality request when writing TIFF. #3110
• Fix broken oiiotool --dumpdata output. #3131
• Fix possible bad data alignment and SIMD assumptions inside TextureSystems internals. #3145
• Field3D, which is no longer actively supported, now has support disabled in the default build. To enable Field3D support, you must build with -DENABLE_FIELD3D=1. Note that we expect it to be no longer supported at all, beginning with OIIO 2.4. #3140
• Build: Address new warnings revealed by clang 13. #3122
• Build: Fix when building with Clang on big-endian architectures. #3133
• Build: Fix occasional build breaks related to OpenCV headers. #3135
• Build: Improvements to NetBSD and OpenBSD support. #3137.
• docs: Add an oiiotool example of putting a border around an image. #3138
• docs: Fix explanation of ImageCache "falure_retries" attribute. #3147

Release 2.3.8 (1 Oct 2021) -- compared to 2.3.7

• Fix ImageBuf::read() bug for images of mixed per-channel data types. #3088
• Fix crash that could happen with invalidly numbered UDIM files. #3116
• Better catching of exceptions and other error handling when OpenColorIO 1.x is used but encounters an OpenColorIO 2.x config file. #3089 #3092 #3095
• Ensure that OpenColorIO doesn't send info messages to the console if no config is found. #3113
• Fix: make sure ImageSpec deserialization works for arbitrary attribs. #3066
• oiiotool -ch now has greatly reduced cost (no useless allocations or copies) when the channel order and names don't change. #3068
• oiiotool --runstats is now much better about correctly attributing I/O time to -i instead of to the subsequent operations that triggers the read. #3073
• TIFF output now supports IO proxies. #3075 #3077
• Improved finding of fonts (by IBA::render_text and oiiotool --text). It now honors environment variable $OPENIMAGEIO_FONTS and global OIIO attribute "font_searchpath" to list directories to be searched when fonts are needed. #3096
• We no longer install a FindOpenImageIO.cmake module. It was incomplete, out of date, and wholly unnecessary now that we correctly export a config file OpenImageIOConfig.cmake and friends. #3098
• When building against OpenEXR 3.1+, use of the OpenEXRCore library no longer requires a build-time option, but instead is always available (though off by default) and can be enabled by an application setting the OIIO global attribute "openexr:core" to 1. #3100
• dev: Timer::add_seconds and add_ticks methods. #3070
• dev: Add round_down_to_multiple() and improve round_to_multiple() to correctly handle cases where the value is less than 0. #3104

Release 2.3 (1 Sept 2021) -- compared to 2.2

New minimum dependencies and compatibility changes:

• C++ standard: C++14 is now the minimum (gcc 6.1 - 11.2, clang 3.4 - 12, MSVS 2017 - 2019, icc 17+). The default C++ standard mode, if none is explicitly specified, is now C++14. #2918 (2.3.4) #2955 #2977 (2.3.5)
• FFMmpeg (optional) dependency minimum is now 3.0 (raised from 2.6). #2994
• OpenCV (optional) dependency minimum is now 3.0 (raised from 2.0). #3015

New major features and public API changes:

• Changes and clarifications to geterror() in all classes that have one:
  • geterror() now takes an optional clear parameter controls if the pending error is cleared as well as retrieved (default true).
  • All classes with geterror() are ensured to have has_error().
  • geterror() appends to the pending error message, if one is already present but not retrieved. Appending errors will be automatically separated by newlines, also any newline at the end of a geterror call will be stripped. #2740 (2.3.0.1)
• ImageInput error messages are now thread-specific. This prevents multiple threads simultaneously reading from the same ImageInput from getting the other thread's error messages. But it means you must always retrieve an error with getmessage() from the same thread that made the read call that generated the error. #2752 (2.3.0.1)
• ImageInput and ImageOutput have removed several fields (like the m_mutex) and instead now use a PIMPL idiom that hides internals better from the ABI. If you had a custom ImageInput/Output class that directly accessed the m_mutex, replace it instead with calls to ImageInput::lock() and unlock() (and ImageOutput). #2752 (2.3.1.0)
• Clarify that ImageBuf methods subimage(), nsubimages(), miplevel(), nmipevels(), and file_format_name() refer to the file that an ImageBuf was read from, and are thus only meaningful for ImageBuf's that directly read from files. "Computed" or copied ImageBuf's are solo images in memory that no longer correspond to a file even if the input to the computation was from a file. #2759 (2.3.0.1/2.2.9)
• New get_extension_map() returns a map that list all image file formats and their presumed file extensions. #2904 (2.3.4)
• Overhaul of how we handle "thumbnails" (small preview images embedded in the headers of some image file formats) #3021 (2.3.7):
  • Thumbnails no longer embedded in the ImageSpec as "thumbnail_image" metadata of a big character array blob.
  • ImageInput, ImageBuf, and ImageCache have varieties of get_thumbnail() method that returns the thumbnail as an ImageBuf. If this is not called, ideally the reader will not undergo the expense of reading and storing thumbnail data.
  • ImageOutput and ImageBuf have set_thumbnail() to communicate a thumbnail image as an ImageBuf.
  • The net effect is that reading files and retrieving ImageSpec's should be more efficient for apps that don't have a use for thumbnails.
• Significant improvements to UDIM handling in ImageCache/TextureSystem:
  • New UDIM texture name patterns recognized: %(UDIM)d is the Houdini convention, and _u##v## is for Animal Logic's internal renderer. #3006 (2.2.16/2.3.6)
  • It is now permissible for get_texture_info()/get_image_info() to retrieve metadata for UDIM patterns -- previously it failed, but now it will succeed in retrieving any metadata as long as it is present and has the same value in all the matching "UDIM tile" panels. #3049 (2.3.7)
  • TextureSystem now exposes methods is_udim(), resolve_udim(), inventory_udim() that should be helpful for apps dealing with UDIM textures. See the documentation for details. #3054 (2.3.7)
  • Performance improvements when using UDIM textures. #3049 (2.3.7)
• ImageBuf, when "wrapping" an app-owned buffer, now allows explicit specification of stride lengths. This allows you to wrap a buffer that has internal padding or other non-contiguous spacing of pixels, scanlines, or image planes. #3022 (2.3.6)
• oiiotool new commands and options:
  • --pastemeta takes two images as arguments, and appends all the metadata (only) from the first image onto the second image's pixels and metadata, producing a combined image. #2708 (2.3.0.0)
  • --chappend and --siappend both allow an optional modifier :n= to specify the number of images from the stack to be combined (default n=2). #2709 (2.3.0.0)
  • --fit now takes an additional optional modifier: fillmode= with choices of letterbox (default), width, and height. #2784 (2.3.2.0)
  • --autocc now has an optional modifier :unpremult=1 that causes any color transformations related to autocc to unpremultiply by alpha before the transformation and then re-premultiply afterwards, exactly the same control that exists for individual --colorconvert but never existed for autocc. #2890 (2.3.3)
  • --list-formats lists all the image file formats that OIIO knows about, and for each, the associated file extensions. #2904 (2.3.4)
  • --skip-bad-frames causes an error (such as an input file not being found) to simply skip to the next frame in the frame range loop, rather that immediately exiting. #2905 (2.3.4)
  • When doing expression substitution, {getattribute(name)} will be replaced by the value that OIIO::getattribute(name, ...) would retrieve. #2932 (2.3.4)
  • --missingfile (which takes a subsequent argument of error, black, or checker) determines the behavior when an input image file is missing (the file does not exist at all, does not include cases where the file exists but there are read errors). The default value of error matches the old behavior: report an error and terminate all command processing. Other choices of black or checker will continue processing but substitute either a black or checkerboard image for the missing file. #2949 (2.3.4)
  • --printinfo prints verbose metadata info about the current top image on the stack. #3056 (2.3.7)
  • --printstats prints statistics about the current top image on the stack, and optionally can limit the statistics to a rectangular subregion of the image. #3056 (2.3.7)
  • Expanded expression now support the following new metadata notations: META, METABRIEF, and STATS. #3025 (2.3.6)
  • --mosaic now takes optional fit=WxH modifier that lets you set the "cell" size, with all constituent images resized as needed (similarly to if you used --fit on each individually). This is helpful for creating contact sheets without having to resize separately or to know the resolution of the original images. #3026 (2.3.6)
  • REMOVED --histogram which had been deprecated and undocumented since before OIIO 2.0. #3029 (2.3.6)
• Python bindings:
  • When transferring blocks of pixels (e.g., ImageInput.read_image() or ImageOutput.write_scanline()), "half" pixels ended up mangled into uint16, but now they use the correct numpy.float16 type. #2694 (2.3.0.0)
  • The value passed to attribute(name, typedesc, value) can now be a tuple, list, numpy array, or scalar value. #2695 (2.3.0.0)
  • Added Python bindings for the TextureSystem. #2842
  • Add the previously (inadvertently) omitted enum value for ImageBufAlgo.MakeTxBumpWithSlopes. #2951 (2.3.4)
• Environment variables:
  • CUE_THREADS env variable, if set, is now honored to set the default size of the OIIO thread pool. This helps to make OIIO-based apps be good citizens when run as OpenCue jobs. #3038 (2.3.7)
• Library organization:
  • All the utility classes are now in libOpenImageIO_Util only and libOpenImageIO depends on and links to libOpenImageIO_Util, rather than the utility classes being defined separately in both libraries. #2906 (2.3.4)
  • Include file change: imagebuf.h no longer includes imagecache.h. It should never have needed to, since it didn't need any of its declarations. Other code that should always have included both headers, but inadvertently only included imagebuf.h, may now need to add an explicit #include <OpenImageIO/imagecache.h>. #3036 (2.3.7)
• Important change to Makefile wrapper: We have a 'Makefile' that just wraps cmake for ease of use. This has changed its practice of putting builds in build/ARCH to just build (and local installs from dist/ARCH to dist) to better match common cmake practice. So where your local builds end up may shift a bit. #3057 (2.3.7)
• Deprecations: A number of long-deprecated functions and methods have been given deprecation attributes that will cause warnings if you use them. They will eventually be removed entirely at the next "breaking" release (3.0, whenever that is). #3032 (2.3.7)

Performance improvements:

• Speed up BMP reading by eliminating wasteful allocation and copying done on each scanline read. #2934 (2.3.4)
• For IBA::to_OpenCV(), improve efficiency for certain image copies. #2944 (2.3.4)
• Fix runaway parsing time for pathological XMP metadata. #2968 (2.3.5/2.2.15)
• TextureSystem reduction in overhead when using UDIM textures. #3049 (2.3.7)

Fixes and feature enhancements:

• Fix a situation where if an ImageBuf backed by an ImageCache reads an image, then the image changes on disk, then another ImageBuf or ImageCache tries to read it, it could end up with the old version. This involved some strategic cache invalidation when ImageBuf's write images to disk. #2696 (2.3.0.0)
• Improve parsing of XMP records in metadata: more correct handling of lists/sequences, better inference of types that look like int or float (rather than forcing unknown fields into strings), fixed bugs in parsing rational values. #2865 (2.2.12/2.3.3)
• ImageBuf/ImageBufAlgo:
  • IBA::contrast_remap() fixes bug that could crash for very large images #2704 (2.3.0.0)
  • Fix stack overflow crash in IBA::colorconvert of unusually wide images. #2716 (2.3.0.1/2.2.8)
  • Fix IBA::make_texture() incorrectly setting tile sizes. #2737 (2.3.0.1/2.2.8)
  • IBA::make_texture() now correctly propagates error messages, which can be retrieved via the global OIIO::geterror() call. #2747 (2.3.0.1)
  • IBA::fit() now takes a fillmode parameter that controls exactly how the resize will occur in cases where the aspect ratio of the new frame doesn't exactly match that of the source image. The old way (and the default value now) is "letterbox", but now also "width" and "height" modes are allowed. See fit() documentation for details. #2784 (2.3.2.0)
  • IBA::fit() fixes some slight ringing at image edges when using a combination of black wrap mode and a filter with negative lobes. #2787 (2.3.2.0)
  • Fix: ociolook() and ociofiletransform() internally reversed the order of their inverse and unpremult arguments, making it hard to select the inverse transformation. #2844 (2.3.3/2.2.11)
  • Fix crash for certain calls to ImageBuf::set_write_format() when writing files that support per-channel data types. #2885 (2.3.3)
  • Fix: IBA::fillholes_pushpull did not correctly understand which channel was alpha when generating subimages. #2939 (2.3.4)
  • Fix: IBA::render_text did not properly account for non-1 alpha of the text color. #2981 (2.3.5/2.2.15)
  • IBA::colorconvert, colormatrixtransform, ociolook, ociodisplay, and ociofiletransform have been fixed so that if input is more than 4 channels, the additional channels will be copied unchanged, rather than inadvertently set to 0. #2987 (2.3.5/2.2.16)
  • Thread safety has been improved for ImageBuf::init_spec() and read() (though no problem was ever reported in the wild). #3018 (2.3.6)
  • render_text() now accepts text strings with embedded linefeeds and will turn them into multiple lines of rendered text. #3024 (2.3.6)
• ImageCache/TextureSystem/maketx:
  • Fix ImageCache bug: add_tile/get_tile not properly honoring when chend < chbegin it should get all channels. #2742 (2.3.0.1/2.2.8)
  • ImageBufAlgo::make_texture() (as well as maketx and oiiotool -otex) clamp half values to their maximum finite range to prevent very large float inputs turning into Inf when saved as half values. #2891 (2.3.3)
  • Fix crash when sampling non-zero-base channels. #2962 (2.3.5/2.2.15)
  • IBA::make_texture() rejects "deep" input images, since they cannot be made into textures. Doing this could previously crash. #2991 (2.3.5/2.2.16)
  • maketx and oiiotool -otex have fixed double printing of error messages #2992 (2.3.5).
  • Making bumpslopes textures now allows scaled slopes UV normalization. This is exposed as new maketx argument --uvsopes_scale, or passing the attribute uvslopes_scale (int) to make_texture(). #3012 (2.3.6)
  • There is a new variety of ImageCache::invalidate() that takes an ImageHandle* argument instead of a filename. #3035 (2.3.7)
• oiiotool:
  • --resize of images with multi-subimages could crash. #2711 (2.3.0.0)
  • Improve oiiotool's guessing about the desired output format based on inputs (in the absence of -d to specify the format). #2717 (2.3.0.1/2.2.8)
  • --text now accepts text strings with embedded linefeeds and will turn them into multiple lines of rendered text. #3024 (2.3.6)
• BMP
  • Fix reading BMP images with bottom-to-top row order. #2776 (2.3.1.1/2.2.9)
  • Correctly read BMP images of the older V1 variety without crashing. #2899 (2.3.3/2.2.13)
  • Fix error in the rightmost pixel column when reading 4 bpp images with odd horizontal resolution. #2899 (2.3.3/2.2.13)
  • BMP reads now return metadata "bmp:bitsperpixel" (only when not 24 or 32) to indicate non-whole-byte channels sizes in the file, and "bmp:version" to indicate the version of the BMP format. #2899 (2.3.3/2.2.13)
  • Speed up BMP reading by eliminating wasteful allocation and copying done on each scanline read. #2934 (2.3.4)
  • For BMP files that are 8 bits per pixel and all palette entries have R == G == B values, read the file as an 8-bit grayscale image instead of needlessly promoting to a full RGB 3-channel image. #2943 (2.3.4)
  • Full support for reading RLE-compressed BMP images. #2976 (2.3.5/2.2.15)
  • Write single channel BMP as 8 bit palette images. #2976 (2.3.5/2.2.15)
• DPX
  • Output to DPX files now supports IOProxy. (Input already did.) #3013 (2.2.17/2.3.6)
• FFMpeg/movies:
  • Avoid potential crash when a frame can't be read. #2693 (2.3.0.0)
  • Several varieties of encoded videos with 12 bits per channel and having alpha were incorrectly reported as 8 bits and without alpha. #2989 (2.3.5/2.2.16)
• GIF
  • Support UTF-8 filenames on Windows for GIF files. #2777 (2.3.2.0)
  • Fix error checking for non-existent GIF files. #2886 (2.3.3)
• HEIC
  • Fix error decoding Apple HEIF files. #2794/#2809 (2.3.2.0)
  • Better valid_file() check for HEIF. #2810 (2.3.2.0)
  • Enabled AVIF decoding of heic files (requires libheif >= 1.7 and for it to have been built with an AV1 encoder/decoder). #2811 #2812 #2814 #2818 (2.3.3.0)
• IFF
  • Fix broken reads of 16 bit iff files. #2736 (2.3.0.1/2.2.8)
• JPEG
  • Allow reading of JPEG files with mildly corrupted headers. #2927 (2.3.4)
• OpenEXR:
  • Fix rare crash that was possible when multithreaded writing openexr files. #2781 (2.3.2.0)
  • Improved error reporting when errors are encountered writing OpenEXR files. #2783 (2.3.2.0)
  • Fix potential crash parsing OpenEXR header that contains Rational attributes with certain values. #2791 (2.2.10/2.3.2)
  • EXPERIMENTAL: When building against OpenEXR 3.1, the OIIO CMake option -DOIIO_USE_EXR_C_API=ON will use a new OpenEXR API that we think will allow higher performance texture reads in a multithreaded app. This has not yet been benchmarked or tested thoroughly. #3009 #3027 (2.3.6)
  • The reader no longer renames file metadata "version" into the special "openexr:version" that would indicate the OpenEXR file format version of the file. That's never what it meant! It really was just arbitrary metadata. #3044 (2.3.7)
• PNG
  • Read Exif data from PNG files. #2767 (2.3.1.1/2.2.9)
• PSD
  • Add support for reading ISD profiles for PSD input. #2788 (2.3.2.0)
  • Fix loading PSB files with cinf tags. #2877 (2.2.12/2.3.2)
• RAW:
  • Additional input configuration hints to control options in the underlying LibRaw: "raw:user_flip" #2769 (2.3.1.0) "raw:balance_clamped", "raw:apply_scene_linear_scale", "raw:camera_to_scene_linear_scale" #3045 (2.3.7)
  • Correctly handle RAW files with Unicode filenames on Windows. #2888 (2.3.3)
  • Fix garbled output when raw:Demosaic hint is "none". #3045 (2.3.7)
• Targa
  • Fix potential crash when reading files with no thumbnail. #2903 (2.3.3/2.2.13)
  • Fix alpha handling for some files. #3019 (2.3.6)
• TIFF:
  • Fix broken reads of multi-subimage non-spectral files (such as photometric YCbCr mode). #2692 (2.3.0.0)
  • Fix spec() and spec_dimensions() for MIPmapped TIFF files, they did not recognize being asked to return the specs for invalid subimage indices. #2723 (2.3.0.1/2.2.7)
  • Add ability to output 1bpp TIFF files. #2722 (2.3.0.1/2.2.7)
  • Fix reading TIFF files with "separate" planarconfig and rowsperstrip more than 1. #2757 (2.3.0.1/2.2.9)
  • Fix incorrect reading of tiled TIFF files using certain rare TIFF features that also have a vertical resolution that is not a whole multiple of the tile size. #2895 (2.3.3/2.2.13)
  • Support IOProxy for reading TIFF files. #2921 (2.3.4)
  • TIFF plugin now properly honors caller request for single-threaded operation. #3016 (2.3.6)
• WebP:
  • Add support for requesting compression "lossless". #2726 (2.3.0.1/2.2.8)
  • Input improvements including: RGB images are kept as RGB instead of always adding alpha; more efficient by skipping alpha premultiplication when it's unnecessary; now can read animated WebP images as multi-subimage files. #2730 (2.3.0.1/2.2.8)
• Fix memory leak during decoding of some invalid Exif blocks. #2824
• Fix possible divide-by-zero error in read_image/read_scanlines for invalid image sizes (usually from corrupt files). #2983 (2.3.5/2.2.16)

Developer goodies / internals:

• Internals now use C++11 final keywords wherever applicable. #2734 (2.3.0.1)
• More internals conversion of old Strutil::sprintf to Strutil::fmt::format and related changes. #2889 (2.3.3)
• Redundant format conversion code removed from imageio.cpp #2907 (2.3.4)
• Eliminate direct output to std::cerr and std::cout by library calls. #2923 (2.3.4)
• argparse.h:
  • ArgParse::abort() lets the response to a command line argument signal that no further arguments should be parsed. #2820 (2.3.3/2.2.11)
• color.h:
  • New ColorConfig::OpenColorIO_version_hex() returns the hex code for the version of OCIO we are using (0 for no OCIO support). #2849 (2.3.3)
• farmhash.h:
  • Clean up all non-namespaced preprocessor symbols that are set by this header and may pollute the caller's symbols. #3002 (2.2.16/2.3.6)
• filesystem.h:
  • New Filesystem::generic_filepath() returnss a filepath in generic format (not OS specific). #2819 (2.3.3/2.2.11)
  • Improve exception safety in Filesystem directory iteration. #2998 (2.2.16/2.3.6)
  • New filename_to_regex() makes a filename "safe" to use as a regex pattern (for example, properly backslashing any . characters). #3046 (2.3.7)
  • Some methods that used to take a const std::string& now take a string_view. #3047 (2.3.7)
• fmath.h:
  • Use CPU intrinsics to speed up swap_ending (by 8-15x when swapping bytes of large arrays). #2763 (2.3.1.0)
• hash.h:
  • farmhash::inlined::Hash now is constexpr and works for Cuda. #2843 (2.3.3) #2914 #2930 (2.3.4)
• oiioversion.h:
  • New macros OIIO_VERSION_GREATER_EQUAL and OIIO_VERSION_LESS. #2831 (2.3.3/2.2.11)
• platform.h:
  • New macro OIIO_INLINE_CONSTEXPR, equivalent to inline constexpr for C++17, but just constexpr for C++ <= 14. #2832 (2.3.3/2.2.11)
• simd.h:
  • Fix incorrect ARM NEON code in simd.h. #2739 (2.3.0.1/2.2.8)
• span.h:
  • std::size() and std::ssize() should work with OIIO::span now. #2827 (2.3.3/2.2.11)
• string_view.h:
  • std::size() and std::ssize() should work with OIIO::string_view now. #2827 (2.3.3/2.2.11)
  • More thorough constexr of string_view methods. #2841 (2.3.3)
• strongparam.h:
  • New StrongParam helper for disambiguating parameters. #2735 (2.3.2)
• strutil.h:
  • Strutil splits() and splitsv() should return no pieces when passed an empty string. (It previously erroneously returned one piece consisting of an empty string.) #2712 (2.3.0.0)
  • Fix build break when strutil.h was included in Cuda 10.1 code. #2743 (2.3.0.1/2.2.8)
  • strhash() is now constexpr for C++14 and higher. #2843 (2.3.3)
  • New Strutil functions: find, rfind, ifind, irfind #2960 (2.3.4/2.2.14) contains_any_char #3034 (2.3.7) rcontains, ircontains #3053 (2.3.7)
• sysutil.h:
  • Extend getenv() to take a default if the environment variable is not found. #3037 #3040 (2.3.7)
• typedesc.h:
  • TypeDesc::basetype_merge(a,b) returns a BASETYPE having the precision and range to hold the basetypes of either a or b. #2715 (2.3.0.0)
  • TypeDesc can now describe 2D and 3D bounding boxes, as arrays of 2 VEC2 aggregates (for 2D) or VEC3 aggregates (for 3D) with "BOX" semantic. The shorthand for these are TypeBox2, TypeBox3 (for float), and TypeBox2i and TypeBox3i for integer or pixel coordinte boxes. #3008 (2.2.17/2.3.6)
• unordered_map_concurrent.h:
  • New methods find_or_insert, nobin_mask(). #2867 (2.2.12/2.3.3)
• ustring.h:
  • ustring internals now have a way to ask for the list of ustrings whose hashses collided. #2786 (2.2.11/2.3.2.0)
  • ustring now guarantees that no two ustrings will return the exact same value for hash(). #2870 (2.3.3)
  • ustring now explicitly disallows embedded NUL (0) characters in the middle of a string. A ustring constructed from such a thing will truncate the string after the first NUL. #3326 (2.4.0.2)

Build/test system improvements and platform ports:

• CMake build system and scripts:
  • Instead of defaulting to looking for Python 2.7, the OIIO build now defaults to whatever Python is found (though a specific one can still be requested via the PYTHON_VERSION variable). #2705 (2.3.0.0/2.2.8) #2764 (2.3.0.1/2.2.8)
  • Make the OIIO CMake files work properly if OIIO is a subproject. Also various other CMake script refactoring. #2770 (2.3.1.1/2.2.9)
  • Extend checked_find_package with VERSION_MIN and VERSION_MAX #2773 (2.3.1.1/2.2.9), DEFINITIONS and SETVARIABLES #3061 (2.3.7)
  • No longer directly link against python libraries when unnecessary. #2807 (2.2.11/2.3.3)
  • On Windows, fix some linkage problems by changing the pybind11 bindings to make a CMake "shared" library rather than "module". Sounds wrong, but seems to work. We will reverse if this causes problems. #2830 (2.3.3/2.2.11)
  • Improvements to building or linking static libraries. #2854 (2.2.12/2.3.3)
  • Change default STOP_ON_WARNING to OFF for release branches (including this one) so that small change in compiler warnings after our release don't break anybody's builds. (Though we still stop on warnings for CI builds). #2861 (2.2.12/2.3.3)
  • The pkgconfig OpenImageIO.pc was specifying the include path incorrectly. #2869 (2.2.12/2.3.3)
  • Support for CMake 3.20. #2913 #2931 (2.3.4)
  • Be sure to have the namespace include the patch number for pre-release builds from the master branch. #2948 (2.3.4)
  • Use modern style cmake targets for PNG and ZLIB dependencies. #2957 (2.3.4)
  • Propagate C++14 minimum requirement to downstream projects via our cmake config exports. #2965 (2.3.5)
  • Fix exported cmake config files, which could fail if Imath and OpenEXR weren't the at the same version number. #2975 (2.3.5/2.2.15)
  • Change default postfix for debug libraries to _d. (2.3.5)
  • Our CMake checked_find_package is now able to be requested to favor an exported config file, if present, on a package-by-package basis. #2984 (2.3.5/2.2.15)
  • If a package is requested to be disabled, skip its related tests rather than reporting them as broken. #2988 (2.3.5/2.2.16)
  • Better support for running testsuite when the build dir in odd places. #3065 #3067 (2.3.7.1)
  • To prevent accidental overwrite of sensitive areas (such as /usr/local), you now need to explicitly set CMAKE_INSTALL_PREFIX if you want the "install" to not be local to the build area. #3069 (2.3.7.1)
• Dependency version support:
  • C++20 is now supported. #2891 (2.3.3)
  • Fix deprecation warnings when building with very new PugiXML versions. #2733 (2.3.0.1/2.2.8)
  • Fixes to build against OpenColorIO 2.0. #2765 (2.3.0.1/2.2.8) #2817 #2849 (2.3.3/2.2.11) #2911 (2.3.4)
  • Fix to accommodate upcoming OpenColorIO 2.1 deprecation of parseColorSpaceFromString. #2961 (2.3.5/2.2.15)
  • Work to ensure that OIIO will build correctly against Imath 3.0 and OpenEXR 3.0, as well as Imath 3.1 / OpenEXR 3.1. #2771 (2.3.1.1/2.2.9) #2876 #2678 #2883 #2894 (2.3.3/2.2.12) #2935 #2941 #2942 #2947 (2.3.4)
  • Better finding of OpenJpeg 2.4. #2829 (2.3.3/2.2.11)
  • On Mac, libheif 1.10 is very broken. Don't use that version. #2847 (2.3.3/2.2.11)
  • Fix build break against changes coming in future libtiff, where it is changing from some libtiff-defined integer types to the equivalent stdint.h types. #2848 (2.3.3/2.2.11)
  • Fixes to support the libraw 202101 snapshot (their in-progress 0.21.0). #2850 (2.3.3/2.2.11)
  • More clear warnings about using OpenVDB 8+ when building for C++11, because OpenVDB 8 requires C++14 or higher. #2860 (2.2.12/2.3.3)
  • More gracefully handle building against a custom Imath/OpenEXR even when another exists in the system area. #2876 (2.2.12/2.3.3)
  • Minor fixes to build cleanly against the upcoming Imath 3.0. #2878 (2.2.12/2.3.3)
  • Remove obsolete dependency on Boost random (now use std::random). #2896 (2.3.3)
  • libtiff 4.3 is supported. #2953 (2.3.4)
  • We now include a build_OpenJPEG.bash script that can conveniently build a missing OpenJPEG dependency. (2.3.5/2.2.16)
  • Changes to make it build against TBB 2021. #2985 (2.3.5/2.2.15)
  • Support for building OIIO with gcc 11. #2995 (2.2.16/2.3.6)
  • Fixes to accommodate Imath 3.1 upcoming changes. #2996 (2.2.16/2.3.6)
  • Finding FFMpeg now correctly detects the version. #2994 (2.2.16/2.3.6)
  • FFMpeg minimum version is now >= 3.0. #2999 (2.3.6)
  • Fixes for detecting and using Ptex, among other things got the version wrong. #3001 (2.2.16/2.3.6)
  • Fixes for building against fmt 8.0. #3007 (2.3.6)
  • The OpenCV minimum version is now >= 3.0. #3015 (2.3.6)
  • Fixes to build properly against the upcoming OpenColorIO 2.1. #3050 (2.3.7)
  • Finding boost is more flexible when desiring static libraries. #3031 (2.3.7/2.2.17)
  • FindTBB.cmake module updated to create proper targets. #3060 (2.3.7)
  • All the src/build_scripts/build_*.bash scripts now honor an env variable called DEP_DOWNLOAD_ONLY, which if set will only do the downloads but not the builds. #3058 #3072 (2.3.7)
  • Better finding of OpenCV on Windows. #3062 (2.3.7.1)
• Testing and Continuous integration (CI) systems:
  • Completely get rid of the old appveyor CI. #2782 (2.3.2.0)
  • Test against libtiff 4.2 in the "latest releases" test. #2792 (2.3.2.0)
  • Got Windows CI fully working, bit by bit. #2796 #2798 #2805 #2821 #2826 #2834 #2835 #2836 #2838 #2839 #2840 (2.3.3)
  • Reduce redundant verbosty in CI output logs during dependency building.
  • Modify hash_test to verify correctness and stability of the hashes. #2853 (2.3.3)
  • When building custom OpenEXR with build_openexr.bash, don't have it build the examples. #2857 (2.2.12/2.3.3)
  • Speed up CI by using GitHub 'cache' actions + ccache. #2859 (2.2.12/2.3.3)
  • Separate stages (setup, deps, build, test) into separate GHA "steps" for better logging and understanding of the timing and performance. #2862 (2.2.12/2.3.3)
  • Now actively testing libheif in Linux CI. #2866 (2.2.12/2.3.3)
  • Remove the last vestiges of Travis-CI, which we no longer use. #2871 (2.2.12/2.3.3)
  • For failed tests, add CMake cache and log part of the saved artifacts. (2.2.12/2.3.3)
  • CI now tests build in C++20 mode. #2891 (2.3.3)
  • Our CI clang-format test now uses LLVM/clang-format 11. #2966
  • Test the clang11 + C++17 combo. #3004 (2.3.6)
• Platform support:
  • Fixes for mingw. #2698 (2.3.0.0)
  • Windows fix: correct OIIO_API declaration on aligned_malloc, aligned_free of platform.h. #2701 (2.3.0.0)
  • Fix boost linkage problem on Windows. #2727 (2.3.0.1/2.2.8)
  • Fix warnings when compiling webpinput.cpp on 32 bit systems. #2783 (2.3.2.0)
  • Fix problems with copysign sometimes defined as a preprocessor symbol on Windows. #2800 (2.3.2)
  • Fixes related to Mac M1-based systems: Fix crash in ustring internals #2990 (2.3.5/2.2.15.1)

Notable documentation changes:

• Make Readthedocs generate downloadable HTML as well as PDF. #2746
• Explain how to read image data into separate per-channel buffers. #2756 (2.3.0.1/2.2.8)
• Improve use of breathe and formatting. #2762 (2.3.1.0)
• Remove documentation of deprecated ImageBufAlgo functions. #2762 (2.3.1.0)
• Document missing texture option fields. #2762 (2.3.1.0)
• Starting to use "sphinx_tabs" as a clear way to present how things should be done for different language bindings. #2768 (2.3.1.0)

Release 2.2.21 (1 Jul 2022) -- compared to 2.2.20

• BMP: gain the ability to read some very old varieties of BMP files. #3375
• BMP: better detection of corrupted files with nonsensical image dimensions or total size. #3434
• BMP: protect against corrupted files that have palette indices out of bound. #3435
• ffmpeg: Support for ffmpeg 5.0. #3282
• ffmpeg: protect against possible double-free. #3376
• ffmpeg: make the supported file extension check be case-insensitive. This prevents movie files from being incorrectly unable to recognize their format if they have the wrong capitalization of the file extension. #3364
• hdr/rgbe files: Avoid possible Windows crash when dealing with characters with the high bit set. #3310
• TIFF: fix read problems with TIFF files with non-zero y offset. #3419
• Dev goodies: ustring has added a from_hash() static method #3397, and a ustringhash helper class #3436.
• simd.h fixes for armv7 and aarch32. #3361

Release 2.2.20 (1 Feb 2022) -- compared to 2.2.19

• Fix some address sanitizer failures. #3160
• Build/CI: Deal with OpenColor renaming its master branch to main. #3169
• Windows: Fix error when compiling with MSVC. #3168
• Fix excessive memory usage when saving EXR with many channels. #3176
• TIFF: now works for 16-bit palette images. #3260
• Fix ImageBuf::read bug for images of mixed per-channel data types. #3088

Release 2.2.19 (1 Nov 2021) -- compared to 2.2.18

• Better catching of exceptions thrown by OCIO 1.x if it encounters 2.0 config files. #3089
• Address new warnings revealed by clang 13. #3122
• Fixed some minor python binding bugs. #3074 #3094
• Fix when building with Clang on big-endian architectures. #3133
• Fix occasional build breaks related to OpenCV headers. #3135
• Improvements to NetBSD and OpenBSD support. #3137.
• Fixes to work with the libraw 202110 snapshot. #3143

Release 2.2.18 (1 Sep 2021) -- compared to 2.2.17

• Honor env variable CUE_THREADS (used by OpenCue) to set the default size of OIIO's thread pool. #3038
• Compatibility with OpenColorIO 2.1. #3050
• Dev: Extend Sysutil::getenv() to take a default if the environment variable is not found. #3047 #3048

Release 2.2.17 (1 Aug 2021) -- compared to 2.2.16

• Output to DPX files now supports IOProxy. (Input already did.) #3013
• typedesc.h: TypeDesc can now describe 2D and 3D bounding boxes, as arrays of 2 VEC2 aggregates (for 2D) or VEC3 aggregates (for 3D) with "BOX" semantic. The shorthand for these are TypeBox2, TypeBox3 (for float), and TypeBox2i and TypeBox3i for integer or pixel coordinte boxes. #3008
• Build: Fixes for building against fmt 8.0.0. #3007
• Build: Finding boost is more flexible when desiring static libraries. #3031

Release 2.2.16 (1 Jul 2021) -- compared to 2.2.15

• New UDIM texture name patterns recognized: %(UDIM)d is the Houdini convention, and _u##v## is for Animal Logic's internal renderer. #3006 (2.2.16)
• When doing color space transforms on images with > 4 channels -- the additional channels are now copied unaltered, rather than leaving them black. #2987 (2.2.16)
• FFMpeg: fix some encodings that didn't correctly recognize that they were more than 8 bits, or had alpha. #2989 (2.2.16)
• farmhash.h: Clean up all non-namespaced preprocessor symbols that are set by this header and may pollute the caller's symbols. #3002 (2.2.16)
• Fix crashes on M1 (ARM) based Mac. #2990 (2.2.16)
• Bug fix: avid divide-by-0 error computing chunk size for invalid image sizes. #2983 (2.2.16)
• make_texture (and maketx and oiiotool -otex) no longer crash if you try to make a texture out of a "deep" image; instead it will return an error message. #2991 (2.2.16)
• filesystem.h: Improve exception safety in Filesystem directory iteration. #2998 (2.2.16)
• Build: Improve finding of OpenJPEG. #2979 (2.2.16)
• Build: Support for building OIIO with gcc 11. #2995 (2.2.16)
• Build: Fixes to accommodate Imath 3.1 upcoming changes. #2996 (2.2.16)
• Build: Finding FFMpeg now correctly detects the version. #2994 (2.2.16)
• Build: clang + C++17 + LibRaw < 0.20 are mutually incompatible. Detect this combination and warn / disable libraw under those conditions. #3003 (2.2.16)
• Build: Fix CMake behavior for REQUIRED_DEPS due to a typo. #3011 (2.2.16)
• Build: Fixes for detecting and using Ptex, among other things got the version wrong. #3001 (2.2.16)
• Testing: If a feature is disabled, skip its tests rather than reporting them as broken. #2988 (2.2.16)
• CI: Test the combination of clang and C++17. #3003 (2.2.16)

Release 2.2.15.1 (3 Jun 2021) -- compared to 2.2.15.0

• Fix crash / misbehavior in ustring internals on Apple M1 ARM. #2990

Release 2.2.15 (1 Jun 2021) -- compared to 2.2.14

• BMP improvements: now support reading rle-compressed BMP files; writing single channel grayscale images now save as 8bpp palette images intead of 24bpp; and reading 8bpp where all palette entries have R==G==B looks like a 1-channel grayscale instead of 3-channel RGB. #2976
• Bug: IBA::render_text did not properly account for alpha of the draw color. #2981
• Bug: Fix runaway parsing time for pathological XMP metadata. #2968
• Bug: Fixed a crash is ImageCacheFile::read_unmipped when sampling
• Fix exported cmake config files, which could fail if Imath and OpenEXR weren't the at the same version number. #2975
• Build: Modernize cmake to use targets for PNG and ZLIB. #2957
• Build: Fix to accommodate upcoming OpenColorIO 2.1 deprecation of parseColorSpaceFromString. #2961
• Build: Changes to make it build against TBB 2021. #2985
• Dev: Add Strutil functions: find, rfind, ifind, irfind. #2960

Release 2.2.14 (1 May 2021) -- compared to 2.2.13

• JPEG: Improve readin of files with mildly corrupted headers. #2927
• TIFF: Support IOProxy for input. #2921
• BMP: Improve performance by eliminating wasteful per-scanline allocation and needless data copying. #2934
• Build/CI: Fix all the build_*.bash scripts to not use cmake --config flag, which was harmlessly ignored but is flagged as an error for CMake 3.20. #2931
• Build: More fixes related to supporting a wide range of OpenEXR versions, and making our exported cmake configs correctly transmit dependencies on OpenEXR include paths. #2935 #2941 #2942 #2947
• ImageBufAlgo::fillholes_pushpull: added logic to correctly set the spec's alpha_channel field when generating sub-images. #2939
• Python: MakeTxBumpWithSlopes enum value had been inadvertently omitted from the Python bindings. #2951

Release 2.2.13 (1 Apr 2021) -- compared to 2.2.12

• Get ready for upcoming Imath/OpenEXR 3.0 release. #2883 #2894 #2897
• GIF: Fix error checking for non-existent GIF files. #2886
• Fix crash related to ImageBuf:set_write_format() when used in conjunction with a file format that doesn't support per-channel data types. #2885
• Make RAW files handle Unicode filenames on Windows. #2888
• Make sure OIIO builds cleanly with C++20. #2891
• BMP: Several bug fixes when reading an older (V1) variety of BMP files. #2899
• Targa: fix reading tga files with 0-sized thumbnails. #2903
• TIFF: fix reading of certain tiled TIFF files with the vertical image size is not a whole multiple of the tile size. #2895
• Avoid OpenColorIO v2 exception when color-conversion of single points (we didn't pass a correct stride, thinking that stride isn't used for a single point). #2911
• make_texture: When outputting to a 'half' data format file, clamp filtered values to the half range so large values don't inadvertently get converted to half 'infinite' values. #2892
• Improvements to ustring internals to ensure that no two ustrings ever end up with the same hash() value. #2870
• Fixes for compiler errors when compiling farmhash.h using C++11 mode with newer gcc (6+). #2914

Release 2.2.12 (1 Mar 2021) -- compared to 2.2.11

• Bug fix: Improve parsing of XMP records in metadata: more correct handling of lists/sequences, better inference of types that look like int or float (rather than forcing unknown fields into strings), fixed bugs in parsing rational values. #2865
• Bug fix: Fix loading PSB files with cinf tags. #2877
• Build: Improvements to building or linking static libraries. #2854
• Build: Change default STOP_ON_WARNING to OFF for release branches (including this one) so that small change in compiler warnings after our release don't break anybody's builds. (Though we still stop on warnings for CI builds). #2861
• Build: More clear warnings about using OpenVDB 8+ when building for C++11, because OpenVDB 8 requires C++14 or higher. #2860
• Build: The pkgconfig OpenImageIO.pc was specifying the include path incorrectly. #2869
• Build: More gracefully handle building against a custom Imath/OpenEXR even when another exists in the system area. #2876
• Build: Minor fixes to build cleanly against the upcoming Imath 3.0. #2878
• Dev: hash.h: Make many of the hash functions constexpr. #2843
• Dev: Better unit tests to verify correctness and stability over time of the hash functions. #2853
• Dev: unordered_map_concurrent.h: New methods find_or_insert, nobin_mask(). #2867
• CI: Speed up CI builds by not building OpenEXR example programes. #2857
• CI: Speed up CI by using GitHub 'cache' actions + ccache. #2859
• CI: Separate stages (setup, deps, build, test) into separate GHA "steps" for better logging and understanding of the timing and performance. #2862
• CI: Now actively testing libheif in Linux CI. #2866
• CI: Remove the last vestiges of Travis-CI, which we no longer use. #2871
• CI: For failed tests, add CMake cache and log part of the saved artifacts.
• PSA: Avoid libheif 1.10 on Mac, it is broken. Libheif 1.11 is fine.

Release 2.2.11.1 (1 Feb 2021) -- compared to 2.2.11.0

• Fix build break against Qt 5.15.2 (deprecated enum). #2852

Release 2.2.11 (1 Feb 2021) -- compared to 2.2.10

• Enabled AVIF decoding of heic files (requires libheif >= 1.7 and for it to have been built with an AV1 encoder/decoder). #2811 #2812 #2814 #2818
• oiiotool --help now prints the OCIO version (where it prints the config file and known color space). #2849
• Bug fix: ImageBufAlgo::ociolook() and ociofiletransform() internally reversed the order of their inverse and unpremult arguments, making it hard to select the inverse transformation. #2844
• Fix memory leak during decoding of some invalid Exif blocks. #2824
• Build: Fixed warnings when building against python 2.x. #2815
• Build: No longer directly link against python libraries when unnecessary. #2807
• Build: Better finding of OpenJpeg 2.4. #2829
• Build: On Windows, fix some linkage problems by changing the pybind11 bindings to make a CMake "shared" library rather than "module". Sounds wrong, but seems to work. We will reverse if this causes problems. #2830
• Build: On Mac, libheif 1.10 is very broken. Don't use that version. #2847
• Build: Fix build break against changes coming in future libtiff, where it is changing from some libtiff-defined integer types to the equivalent stdint.h types. #2848
• Build: Some final touches to prepare for release of OpenColor 2.0. #2849
• Build: Fixes to support the libraw 202101 snapshot (their in-progress 0.21.0). #2850
• CI: Got Windows CI fully working, bit by bit. #2796 #2805 #2821 #2826 #2834 #2835 #2836 #2840
• Dev: Some internal rearrangement of span.h and string_view.h (that should not break source or ABI compatibility). std::size() and std::ssize() should work with OIIO::span and OIIO::string_view now. #2827
• Dev: ustring internals now have a way to ask for the list of ustrings whose hashses collided. #2786
• Dev: New Filesystem::generic_filepath() returnss a filepath in generic format (not OS specific). #2819
• Dev: ArgParse::abort() lets the response to a command line argument signal that no further arguments should be parsed. #2820
• Dev: In oiioversion.h, added macros OIIO_VERSION_GREATER_EQUAL and OIIO_VERSION_LESS. #2831
• Dev: In platform.h, added macro OIIO_INLINE_CONSTEXPR, which is equivalent to inline constexpr for C++17, but just constexpr for C++ <= 14. #2832

Release 2.2.10.1 (7 Jan 2021) -- compared to 2.2.10.0

• Fix build break against OpenColorIO v2.0 RC1. #2817

Release 2.2.10 (1 Jan 2021) -- compared to 2.2.9

• GIF: support for UTF-8 filenames on Windows. #2777
• OpenEXR: Fix rare crash during multithreaded output. #2781
• OpenEXR: Fix potential crash parsing OpenEXR header that contains Rational attributes with certain values. #2791
• Improved error reporting for IOFile failures to open the file. #2780
• Build: Fix webp compile break on 32 bit systems. #2783
• Build/Windows: Fix symbol definition conflict with pyconfig.h. #2800
• CI: Test the latest fmt, PugiXML, and pybind11 releases. #2778
• Docs: Add explanation of oiiotool -otex modifiers that were missing from the docs. #2790 Fix some duplicated text. #2785

Release 2.2.9 (1 Dec 2020) -- compared to 2.2.8

• TIFF: Fix reading files with "separate" planarconfig and rowsperstrip more than 1. #2757 (2.3.0.1/2.2.9)
• RAW: add "raw:user_flip" input configuration hint to control this option in the underlying libraw. #2769 (2.3.1.0)
• PNG: Read Exif data from PNG files. #2767
• BMP: Fix reading BMP images with bottom-to-top row order. #2776
• Work to ensure that OIIO will build correctly against the upcoming Imath 3.0 and OpenEXR 3.0.
• Make the OIIO CMake files work properly if OIIO is a subproject. Also various other CMake script refactoring. #2770

Release 2.2.9 (1 Dec 2020) -- compared to 2.2.8

• TIFF: Fix reading files with "separate" planarconfig and rowsperstrip more than 1. #2757 (2.3.0.1/2.2.9)
• RAW: add "raw:user_flip" input configuration hint to control this option in the underlying libraw. #2769 (2.3.1.0)
• PNG: Read Exif data from PNG files. #2767
• BMP: Fix reading BMP images with bottom-to-top row order. #2776
• Work to ensure that OIIO will build correctly against the upcoming Imath 3.0 and OpenEXR 3.0. #2771
• Make the OIIO CMake files work properly if OIIO is a subproject. Also various other CMake script refactoring. #2770

Release 2.2.8 (1 Nov 2020) -- compared to 2.2.7

• Fix that ImageBuf images backed by ImageCache, could hold an outdated copy of the image if it was in the imagecache once, then changed on disk. #2696
• Fix stack overflow crash in IBA::colorconvert of unusually wide images. #2716
• Fix boost linkage problem on Windows. #2727
• Fix broken reads of 16 bit iff files. #2736
• Fix make_texture incorrectly setting tile sizes. #2737
• Fix incorrect ARM NEON code in simd.h. #2739
• Improve oiiotool --chappend and --siappend, allowing an optional modifier ":n=" to specify the number of images from the stack to be combined by having their channels or subimages appended. #2709
• WebP: add support for requesting compression "lossless". #2726
• Improve build system for finding Python, now if a specific version is not requested, default to whichever is found rather than always defaulting to Python 2.7. #2705 #2764
• Fix deprecation warnings when building with very new PugiXML versions. #2733
• Fix ImageCache bug: add_tile/get_tile not properly honoring when chend < chbegin it should get all channels. #2742
• Fix build break when strutil.h was included in Cuda 10.1 code. #2743
• Docs: Make readthedocs generate downloadable htm as well as pdf. #2746
• Improve oiiotool's guessing about the desired output format based on inputs (in the absence of -d to specify the format). #2717
• JPEG output: add support for writing progressive JPEGS (set the attribute "jpeg:progressive" to 1). #2749
• WebP input improvements including: RGB images are kept as RGB instead of always adding alpha; more efficient by skipping alpha premultiplication when it's unnecessary; now can read animated WebP images as multi-subimage files. #2730
• Docs: ImageInput chapter now has an example of reading image data into separate per-channel buffers. #2756
• Fixes to build against recent changes in OpenColorIO v2 master. #2765

Release 2.2.7 (1 Oct 2020) -- compared to 2.2.6

• oiiotool new command: --pastemeta takes two images as arguments, and appends all the metadata (only) from the first image onto the second image's pixels and metadata, producing a combined image. #2708
• TIFF: Fix broken reads of multi-subimage non-spectral files (such as photometric YCbCr mode). #2692
• Python: When transferring blocks of pixels (e.g., ImageInput.read_image() or ImageOutput.write_scanline()), "half" pixels ended up mangled into uint16, but now they use the correct numpy.float16 type. #2694
• Python: The value passed to attribute(name, typedesc, value) can now be a tuple, list, numpy array, or scalar value. #2695
• IBA::contrast_remap() fixes bug that could crash for very large images #2704
• Warn about recommended minimum versions of some dependencies.
• Windows fix: correct OIIO_API declaration on aligned_malloc, aligned_free of platform.h. #2701
• Fix oiiotool crash when --resize was used with multi-subimage files. #2711
• Bug fix in Strutil::splits and splitsv: when input is the empty string, the split should return no pieces. #2712
• Support for libheif 1.9. #2724
• TIFF: Fix spec() and spec_dimensions() for MIPmapped TIFF files, they did not recognize being asked to return the specs for invalid subimage indices. #2723
• TIFF: add ability to output 1bpp TIFF files. #2722

Release 2.2 (1 Sept 2020) -- compared to 2.1

New minimum dependencies:

• pybind11 >= 2.4.2
• openjpeg >= 2.0 (if JPEG-2000 support is desired) #2555 (2.2.2)

New major features and public API changes:

• Improved IOProxy support:
  • ImageInput and ImageOutput now have direct API level support for IOProxy in their open() and create() calls, as well as a new set_ioproxy() method in these classes. #2434 (2.2.0)
  • ImageBuf can now specify a proxy upon construction for reading, and for writing via a set_write_ioproxy() method that applies to subsequent write call. #2477 (2.2.1).
  • DPX input now supports IOProxy. #2659 #2665 (2.2.5)
  • ImageCache (and ImageBuf backed by ImageCache) entries that use IOProxy are careful not to fully "close" their proxies when trying to reclaim space in the file cache (that would be bad, since the proxy can't be re-opened). #2666 (2.2.5)
• Improved support for multi-subimage files:
  • oiiotool: Nearly all operations now allow an optional :subimages=... modifier that restricts the operation to be performed on only a subset of named or indexed subimages. See docs for details. #2582
  • Python ImageBuf.write() variety added that takes an open ImageOutput. This is the key to writing a multi-subimage file (such as a multi-part OpenEXR) using the Python ImageBuf interface. #2640 (2.2.4)
  • Fixes to --croptofull and -o with multi-subimages. #2684 (2.2.6)
• Python bindings:
  • Python bindings have been added for missing ParamValue constructors. We previously exposed the PV constructors from just a plain int, float, or string, but there wasn't an easy way to construct from arbitrary data like there is in C++. Now there is. #2417 (2.2.0)
  • ParamValueList.attribute(), when being passed attributes containing multiple values, now can have those values passed as Python lists and numpy arrays (previously they had to be tuples). #2437 (2.1.11/2.2.0)
  • ImageBufAlgo.color_range_check() is now available to the Python bindings (was previously only C++). #2602 (2.2.3)
  • New variety of ImageBuf.write() that takes an open ImageOutput. This is the key to writing a multi-subimage file (such as a multi-part OpenEXR) using the Python ImageBuf interface. #2640 (2.2.4)
• ImageBuf:
  • Easier direct use of IOProxy with ImageBuf: constructor and reset() for file-reading ImageBuf now take an optional IProxy* parameter, and a new set_write_ioproxy() method can supply an IOProxy for subsequent write(). #2477 (2.2.1)
  • Add ImageBuf::setpixel() methods that use cspan instead of ptr/len. #2443 (2.1.10/2.2.0)
  • Add "missing" reset() varieties so that every IB constructor has a corresponding reset() with the same parameters and vice versa. #2460
• ImageBufAlgo:
  • New repremult() is like premult, but will not premult when alpha is zero. #2447 (2.2.0)
  • New max() and min() functions take the pixel-by-pixel maximum or minimum of two images. #2470 (2.2.1)
• ColorConfig: add OCIO "role" accessors. #2548
• Low-res I/O of images to terminals that support full color and Unicode characters. Just output to a file ending in ".term", and it will convert (on certain terminals) to an image displayed directly in the terminal. #2631 (2.2.4) Try: oiiotool myfile.exr -o out.term

Performance improvements:

• Greatly improved TextureSystem/ImageCache performance in highly threaded situations where access to the cache was a main bottlenecks. In renders of scenes with lots of texture access, with dozens of threads all contending for the cache, we are seeing some cases of 30-40% reduction in total render time. In scenes that are less texture-bottlenecked, or that don't use huge numbers of threads, the improvement is more modest. #2433 (2.2.0)

Fixes and feature enhancements:

• oiiotool:
  • Intelligible error messages (rather than crashes) if you attempt to create an image too big to fit in memory. #2414 (2.2.0)
  • --create and --proxy take an additional optional modifier: :type=name that specifies the type of buffer to be created (the default, as usual, is to create an internal float-based buffer). #2414 (2.2.0)
  • -o optional argument :type=name is a new (and preferred) synonym for what used to be :datatype=. #2414 (2.2.0)
  • --autotrim now correctly trims to the union of the nonzero regions of all subimages, instead of incorrectly trimming all subimages to the nonzero region of the first subimage. #2497 (2.2.1.2)
  • --subimage now has an optional :delete=1 modifier that causes the operation to delete one named or indexed subimage (versus the default behavior of extracing one subimage and deleting the others). #2575 (2.2.3)
  • The list of dependent libraries (part of oiiotool --help) now correctly reports the OpenEXR version. #2604 (2.2.3)
  • Fix: --eraseattrib did not correctly apply to all subimages when -a or :allsubimages=1 were used. #2632 (2.2.4)
• ImageBuf / ImageBufAlgo:
  • Huge ImageBuf allocation failures (more than available RAM) now are caught and treated as an ImageBuf error, rather than crashing with an uncaught exception. #2414 (2.2.0)
  • ImageBuf constructors that are passed an ImageSpec (for creating an allocated writable IB or "wrapping" a user buffer) now check that the spec passed has enough information to know the size of the buffer (i.e., it will be recognized as an error if the width, height, depth, channels, or data type have not been set validly). #2460
  • Fix: ImageBuf::getchannel() did not honor its wrap parameter. #2465 (2.2.1/2.1.12)
  • Fix: IBA::reorient() and IBA::computePixelHashSHA1() did not honor their nthreads parameter. #2465 (2.2.1/2.1.12)
  • resample() has been modified to more closely match resize by using clamp wrap mode to avoid a black fade at the outer edge of the resampled area. #2481
  • Fix: ImageBuf::get_pixels() did not honor the stride parameters. #2487. (2.1.12/2.2.1)
  • Fix resize() to avoid a crash / stack overflow in certain cases of very big images and very large filter kernels. #2643 (2.2.4)
  • Minor improvements to ImageBuf error formatting. #2653 (2.2.5)
• ImageCache / TextureSystem / maketx:
  • New IC/TS attribute "trust_file_extensions", if nonzero, is a promise that all files can be counted on for their formats to match their extensions, which eliminates some redundant opens and format checks in the IC/TS and can reduce needless network/filesystem work. Use with caution! #2421 (2.2.0)
  • texture3d() fixed some cases where derivative results were not correctly copied to the outputs. #2475 (2.2.1)
  • maketx/IBA::make_texture: better error detection and messages when using "overscan" textures with formats that can't support it properly. (Punchline: only OpenEXR textures can do it.) #2521 (2.2.0)
  • Fix possible redundant tile reads in multithread situations (harmless, but makes for redundant I/O). #2557 (2.2.2)
• Python:
  • Fixed a bug that lost certain string arguments, especially when passing a TypeDesc as its string equivalent. #2587 (2.1.16/2.2.3)
  • Fixed broken bindings of ImageSpec.erase_attribute. #2654 (2.1.19/2.2.6)
  • Fix missing ImageInput.read_image(). #2677 (2.1.19/2.2.6)
• Exif read: guard better against out of range offsets, fixes crashes when reading jpeg files with malformed exif blocks. #2429 (2.1.10/2.2.0)
• Fix: ImageSpec::erase_attribute() did not honor its searchtype parameter. #2465 (2.2.1/2.1.12)
• Fix: Some ColorProcessor::apply() methods were not using their chanstride parameters correctly. #2475 (2.1.12)
• Fix: iinfo return code now properly indicates failures for files that can't be opened. #2511 (2.2.2/2.1.13)
• DPX:
  • IOProxy reading is now supported. #2659 (2.2.5)
  • DPX: Add support for reading DPX files from IOProxy (such as from a memory buffer). #2659 #2665 (2.1.19/2.2.6)
• HDR files:
  • Improve performance when reading HDR files out of order (when combined with ImageCache, observed to speed up out-of-order HDR reading by 18x). #2662 (2.2.5)
• JPEG:
  • Fix resolution unit metadata that was not properly set in JPEG output. #2516 (2.2.2/2.1.13)
  • Fix loss of 'config' info upon close/reopen. #2549 (2.2.2)
• OpenEXR:
  • Add support for reading and writing float vector metadata. #2459 #2486
  • Fix bug in the channel sorting order when channels are "X" and "Y" (was reversing the order by confusing "Y" for "luminance"). #2595 (2.1.16/2.2.3)
  • We no longer automatically rename the "worldToNDC" attribute to "worldtoscreen" and vice versa. #2609 (2.2.4)
• PNG:
  • Fix loss of 'config' info upon close/reopen. #2549 (2.2.2)
  • Add output configuration hint "png:filter" to control PNG filter options. #2650 (2.2.5)
  • Improved propagation of PNG write errors. #2655 (2.2.5)
  • Tell libpng to turn off sRGB profile check, which has a known problem of false positives. #2655 (2.2.5)
  • New output option "png:filter" allows control of the PNG filter options. #2650 (2.1.19/2.2.6)
• Raw images:
  • Support for new Canon .cr3 file, but only if you build against libraw >= 0.20.0 developer snapshot. #2484 (2.2.1) #2613 (2.2.4)
  • RAW input: set the "raw:flip" attribute if the underlying libraw did a reorientation. #2572 (2.1.15/2.2.3)
  • Avoid errors (in libraw) that resulted from multiple threads opening raw files at the same time. #2633 (2.2.4)
• RLA:
  • Additional sanity checks and error checks/messages for detecting files that might be first mistaken for RLA files, but actually are not. #2600 (2.2.3)
• TIFF:
  • Internal improvements to handling metadata retrieval for certain unusual tags. #2504 (2.2.2/2.1.13)
  • Fix subtle bug when reading Exif directory in the header. #2540 (2.2.2)
• Video files:
  • Fix possible infinite loop in the FFMpeg-based reader. #2576 (2.1.15/2.2.3)

Developer goodies / internals:

• argparse.h:
  • Complete overhaul of ArgParse to make it more like Python argparse. Please read the extensive comments in argparse.h for documentation. For now, the old ArgParse interface still works, but is considered deprecated. #2531 (2.2.2) #2618 #2622 (2.2.4)
• attrdelegate.h:
  • New as_vec<> method returns the whole attribute as a std::vector. #2528 (2.2.2)
• filesystem.h:
  • Catch previously uncaught exceptions that could happen in certain Filesystem utility calls. #2522 (2.2.2/2.1.13)
  • New write_text_file() convenience function for opening, writing, and closing a text file all in one step. #2597 (2.2.3)
• fmath.h:
  • clamp() is 2x faster. #2491 (2.1.12/2.2.2)
  • Very minor fix to OIIO::clamp(), shouldn't affect normal use with floats at all, but fixed a subtle quasi-bug in OSL. #2594 (2.1.15/2.2.3)
  • madd() is improved especially on platforms without fma hardware #2492 (2.1.12/2.2.2)
  • Perf improvements to fast_sin, fast_cos #2495 (2.1.12/2.2.2)
  • New safe_fmod() is faster than std::fmod. #2495 (2.1.12/2.2.2)
  • New fast_neg is faster than simple negation in many cases, if you don't care that -(0.0) is 0.0 (rather than a true -0.0). #2495 (2.1.12/2.2.2)
  • Add vint4, vint8, and vint16 versions of clamp(). #2617 (2.2.4)
• oiioversion.h:
  • Fix typo that left the OIIO_VERSION_RELEASE_TYPE symbol undefined. #2616 (2.2.4/2.1.16)
  • Add new OIIO_MAKE_VERSION(maj,min,patch) macro that constructs the proper single integer code for a release version. #2641 (2.2.4/2.1.17)
• paramlist.h:
  • New ParamValueList::find_pv() method that is similar to find() but returns a pointer rather than an iterator and nullptr if the attribute is not found. #2527 (2.2.2/2.1.13)
  • Add get_indexed() method to ParamValueList and AttrDelegate. #2526 (2.2.2/2.1.13)
• platform.h:
  • OIIO_PRETTY_FUNCTION definition is more robust for weird compilers (will fall back to __FUNCTION__ if all else fails). #2413 (2.2.0)
  • OIIO_ALIGN definition is more robust, will fall back to C++11 alignas when not a compiler with special declspecs (instead of being a compile time error!). #2412 (2.2.0)
  • A variety of OIIO_PRAGMA_... macros have been added to help deal with compiler-specific pragmas. #2467 (2.2.1)
• simd.h:
  • vfloat3 has added a normalize(), length(), and length2() methods, to more closely match the syntax of Imath::Vec3f. #2437 (2.1.11/2.2.0)
  • fix errors in vbool == and !=. #2463 (2.1.11/2.2.1)
  • Add float3 versions of abs, sign, ceil, floor, and round (they already existed for float4, float8, float16, but not float4). #2612 (2.2.4)
  • Improved support for ARM NEON SIMD (caveat: this is still not well tested). #2614 (2.2.4)
  • Improve performance for many float8/int8 functions and operators when running on only 4-wide hardware, by using two 4-wide instructions instead of reverting to scalar. #2621
• span.h:
  • Allow the constructor from std::vector to allow vectors with custom allocators. #2533 (2.2.2)
• strutil.h / ustring.h:
  • New Strutil::concat() and ustring::concat() concatenate two strings, more efficiently than sprintf("%s%s") by avoiding any unnecessary copies or temporary heap allocations. #2478 (2.2.1)
  • Strutil::upper() and lower() return all-upper and all-lowercase versions of a string (like to_lower and to_upper, but not in-place modifications of the existing string). #2525 (2.2.2/2.1.13)
  • Strutil::repeat() has been internally rewritten to more efficient by avoiding any unnecessary copies or temporary heap allocations. #2478 (2.2.1)
• typedesc.h:
  • TypeDesc has additional helpers of constexpr values TypeFloat2, TypeVector2, TypeVector4, TypeVector2i, TypePointer. #2592 (2.1.16/2.2.3)
• unordered_map_concurrent.h:
  • Fix missing decrement of size() after erase(). #2624 (2.2.4)
• More reshuffling of printf-style vs fmt-style string formatting. #2424 (2.2.0) #2649 (2.2.4)
• Internals: changed a lot of assertions to only happen in debug build mode, and changed a lot that happen in release builds to only print the error but not force a termination. #2435 (2.1.11/2.2.0)
• Internals: Replaced most uses of boost::thread_specific_ptr with C++11 thread_local. #2431 (2.2.0)
• oiiotool: Big overhaul and simplification of internals. #2586 #2589 (2.2.3)

Build/test system improvements and platform ports:

• CMake build system and scripts:
  • New non-default CMake build flag EXTRA_WARNINGS, when turned on, will cause gcc and clang to compile with -Wextra. This identified many new warnings (mostly about unused parameters) and fixes were applied in #2464, #2465, #2471, #2475, #2476. (2.2.1)
  • FindOpenColorIO.cmake now correctly discerns the OCIO version (2.2.1), and now sets up a true imported target. #2529 (2.2.2)
  • FindOpenEXR.cmake has better detection of debug openexr libraries. #2505 (2.2.2/2.1.13)
  • Additional cmake controls to customize required vs optional dependencies: REQUIRED_DEPS (list of dependencies normally optional that should be treated as required) and OPTIONAL_DEPS (list of dependencies normally required that should be optional). The main use case is to force certain optional deps to be required for your studio, to be sure that missing deps are a full build break, and not a successful build that silently lacks features you need. #2507 (2.2.2/2.1.13)
  • Fix exported cmake config file, it was not ensuring that the Imath headers properly ended up in the config include path. #2515 (2.2.2/2.1.13)
  • Change all CMake references to PACKAGE_FOUND to Package_Found (or whatever capitalization matches the actual package name). #2569 (2.2.2)
  • The exported CMake config files now set cmake variable OpenImageIO_PLUGIN_SEARCH_PATH #2584 (2.1.16/2.2.3)
  • Improved hints printed about missing dependencies. #2682 (2.2.6)
• Dependency version support:
  • Pybind11 is no longer auto-downloaded. It is assumed to be pre-installed. A script src/build-scripts/build_pybind11.bash is provided for convenience if you lack a system install. #2503 (2.2.2) Bump the minimum pybind11 version that we accept, to 2.4.2 #2453, and add fixes to allow support of pybind11 2.5. #2637 (2.2.4)
  • fmt libray: Un-embed fmt headers. If they are not found on the system at build time, they will be auto-downloaded. #2439 (2.2.0)
  • Support for building against libraw 0.20. #2484 (2.2.1) #2580 (2.2.3)
  • Build properly against OpenColorIO's current master (which is the in-progress work on OCIO v2). #2530 (2.2.2)
  • Fix static boost to not overlink on Windows. #2537 (2.2.2)
  • Fix build breaks against TOT libtiff master, which had #define clashes with our GPSTag enum values. #2539 (2.2.2)
  • Ensure compatibility and clean builds with clang 10. #2518 (2.2.2/2.1.3)
  • Support verified for gcc 10, added to CI tests. #2590 (2.2.3)
  • Support for Qt 5.15. #2605 (2.2.3)
  • Fixes to support OpenColorIO 2.0. #2636 (2.2.4)
  • Build against more recent versions of fmtlib. #2639 (2.2.4)
  • Included scripts to download and build libtiff #2543 (2.1.13/2.2.2), PugiXML #2648 (2.2.4), zlib, libpng, libjpeg-turbo. #2663 (2.2.5)
  • Minor fixes for libheif 1.8. #2685 (2.2.6)
  • Add a build_libtiff.bash script to make it easy to build the libtiff dependency. #2543 (2.1.13/2.2.2)
  • "tinyformat" is no longer used, even optionally. We have switched entirely to fmtlib, which is more similar to the upcoming C++20 std::format. #2647 (2.2.4)
• Testing and Continuous integration (CI) systems:
  • Mostly retire TravisCI for ordinary Linux x64 and Mac builds, now we rely on GitHub Actions CI. Nightly test added. Use ASWF docker images to test exactly against VFX Platform 2019 and 2020 configurations. #2563 (2.2.2) #2579 (2.2.3)
  • Add Travis test for arm64 (aka aarch64) builds. This is still a work in progress, and not all testsuite tests pass. #2634 (2.2.4)
  • Our CI tests now have a "bleeding edge" matrix entry that tests against the current TOT master build of libtiff, openexr (#2549), and pybind11 (#2556). (2.2.2)
  • GitHub CI tests, when they fail, leave behind an "artifact" tar file containing the output of the tests, so that they can be easily downloaded and inspected (or used to create new reference output). #2606 (2.2.4)
  • CI Mac tests switch to Python 3.8. (2.2.4)
  • Windows CI switched from using Vcpkg to building its own dependencies. #2663 (2.2.5)
  • Testing of TGA now assumes the test images are in the oiio-images project, not separately downloaded (the download location disappeared from the net). #2512 (2.2.2)
  • Beef up OpenEXR compliance tests, many more examples from openexr-images, including many corrupted image failure cases. #2607 (2.2.4)
• Progress on support for using Conan for dependency installation. This is experimental, it can't yet build all dependencies. Work in progress. #2461 (2.2.1)
• The version of gif.h that we embed for GIF output has been updated. #2466 (2.2.1)
• The farmhash functions have been cleaned up to be more careful that none of their internal symbols are left visible to the linker. #2473 (2.2.1)
• Clarification about .so name versioning: In supported releases, .so contains major.minor, but in master (where ABI is not guaranteed stable, we name major.minor.patch). #2488 (2.2.1)
• Protect against certain compiler preprocessor errors for user programs that include strutil.h but also include fmt on its own. #2498. (2.1.12/2.2.2)
• Build: All the build_foo.bash helper scripts now use set -ex to ensure that if any individual commands in the script fails, the whole thing will exit with a failure. #2520 (2.2.2/2.1.3)
• Fix compiler warning about incorrect extra braces. #2554 (2.2.2)
• All build-scripts bash scripts now use /usr/bin/env to find bash. #2558 (2.2.2)
• Avoid possible link errors by fully hiding IBA functions taking IplImage parameters, when no OpenCV headers are encountered. #2568 (2.2.2)
• In (obsolete) FindOpenImageIO.cmake, avoid CMake warnings by changing the name OPENIMAGEIO_FOUND -> OpenImageIO_FOUND. #2578 (2.2.3)
• Moved headers that are not part of OIIO's supported public API, but that still must be installed to be transitively included, do a "detail" subdirectory. #2648 (2.2.4)
• Fix many Mingw compiler warnings. #2657 (2.1.19/2.2.5)
• Windows: Improve Strutil::get_rest_arguments() handling of long path syntax ("\\?\" style). #2661 (2.1.19/2.2.6)
• Fix compilation error with armv7 + x86. #2660 (2.2.6)

Notable documentation changes:

• Many enhancements in the ImageBuf chapter. #2460 (2.1.11/2.2.0)
• The LICENSE-THIRD-PARTY.md file has been reorganized to be clearer, grouping parts with identical licenses. #2469 (2.2.1) And renamed to "THIRD-PARTY.md" to avoid confusing GitHub's reporting of the project's license. (2.2.6)
• Many fixes to the new readthedocs documentation, especially fixes to section cross-references and links.
• Improved INSTALL instructions. (2.2.2/2.1.13)
• Fix a variety of breaks on ReadTheDocs. #2581
• Improve the way we discuss optional modifiers.
• Document the PNG output controls for compression level. #2642 (2.2.4)
• Lots of spell check / typo fixes in docs and comments. #2678 (2.2.6)
• INSTALL.md: remove misleading old Windows build instructions. #2679 (2.2.6)
• New file .git-blame-ignore-revs lists the hashes of commits that only performed bulk reformatting, so that they don't misattribute authorship or modification date. Everybody do this in your local repo: git config blame.ignoreRevsFile .git-blame-ignore-revs #2683 (2.2.6)

Release 2.1.19 (1 Sep 2020) -- compared to 2.1.18

• DPX: Add support for reading DPX files from IOProxy (such as from a memory buffer). #2659 #2665
• PNG: New output option "png:filter" allows control of the PNG filter options. #2650
• Python: Fix binding of ImageSpec.erase_attribute. #2654
• Python: Fix missing ImageInput.read_image(). #2677
• Windows: Improve Strutil::get_rest_arguments() handling of long path syntax ("\\?\" style). #2661
• MinGW: Fix a variety of compiler warnings on this platform. #2657
• Fix build on Elbrus 2000 architecture. #2671

Release 2.1.18 (1 Aug 2020) -- compared to 2.1.17

• Python ImageBuf.write() added a variety that takes an open ImageOutput. This is the key to writing multi-subimage files from Python. #2640
• oiiotool --eraseattrib fixed: was not applying to all subimages. #2632
• RAW: Improve thread safety when more than one thread might be opening different raw files at the same time. #2633
• unordered_map_concurrent fixed a missing size decrement upon erase(). #2624
• Fixes to support certain recent pybind11 changes. #2637
• Fixes to support OpenColorIO v2. #2636
• Fixes to support more recent fmtlib versions. #2639
• PNG: document the "png:compressionLevel" output hint. #2642
• In oiioversion.h, add a OIIO_MAKE_VERSION macro that constructs the integer code for a particular major/minor/patch release. #2641
• 2.1.18.1: Fix version number which for 2.1.18.0 unfortunately still said it was 2.1.17.

Release 2.1.17 (1 Jul 2020) -- compared to 2.1.16

• Build: Use the discovered python binary name, to address the Fedora restriction that you must use "python2" or "python3" by name. #2598
• Docs: ImageBufAlgo::nonzero_region had been inadvertently left out of the Python chapter.
• Improve RLA reader's ability to detect corrupt or non-RLA files, which fixes crashes you could get from trying to read non-image files. #2600
• Support for building against Qt 5.15. (Note: Qt support is only needed for the "iv" viewer.) #2605
• Fixes to support LibRaw 0.20 (which is currently in beta3). Note that this will make it incompatible with 0.20 beta1 and beta2, due to a fixed typo of a struct field in one of the LibRaw's headers. #2613
• oiioversion.h: fix typo that left the OIIO_VERSION_RELEASE_TYPE symbol undefined. #2616

Release 2.1.16 (1 Jun 2020) -- compared to 2.1.15

• OpenEXR: Fix bug in the channel sorting order when channels are "X" and "Y" (was reversing the order by confusing "Y" for "luminance"). #2595
• Python: Fixed a bug that lost certain string arguments, especially when passing a TypeDesc as its string equivalent. #2587
• fmath: Very minor fix to OIIO::clamp(), shouldn't affect normal use with floats at all, but fixed a subtle quasi-bug in OSL. #2594
• TypeDesc has additional helpers of constexpr values TypeFloat2, TypeVector2, TypeVector4, TypeVector2i, TypePointer. #2592
• Build: The exported CMake config files now set cmake variable OpenImageIO_PLUGIN_SEARCH_PATH #2584
• Docs: improvements and fixes to broken page rendering.

Release 2.1.15 (11 May 2020) -- compared to 2.1.14

• RAW input: set the "raw:flip" attribute if the underlying libraw did a reorientation. #2572
• Movie files: Fix possible infinite loop in the FFMpeg-based reader. #2576
• Fixes to allow building against the forthcoming LibRaw 0.20 release. #2484
• Documentation fixes. #2581

Release 2.1.14 (1 May 2020) -- compared to 2.1.13

• JPEG & PNG: Fix loss of 'config' hints upon close and reopen that could happen in cases where scanlines were accessed out of order. #2549
• TIFF: Fix subtle bug when reading certain Exif directories in the header. #2540
• Added OCIO role accessors to the ColorConfig class. #2548
• Improve error messages when overscan textures are not possible. #2521
• Build: fix problems when compiling against current libtiff master (symbol clash on GPSTAG values). #2539
• Build: Fix static boost to not overlink. #2537.
• Fix some problems with the docs. #2541
• AttrDelegate::as_vec<> returns the whole attribute as a std::vector. #2528
• Add a build_libtiff.bash script to make it easy to build the libtiff dependency. #2543

Release 2.1.13 (1 Apr 2020) -- compared to 2.1.12

• Fix: iinfo return code now properly indicates failures for files that can't be opened. #2511
• Fix: Catch previously uncaught exceptions that could happen in certain Filesystem utility calls. #2522
• Fi: Some span<> methods involving std::vector now will work properly with vectors that have custom allocators. #2533
• Fix: ParamValueList add_or_replace() was failing to "replace" if the new attribute had a different type than the existing one. #2527
• Fix: Fix resolution unit metadata that was not properly set in JPEG output. #2516
• Build: Additional cmake controls to customize required vs optional dependencies -- REQUIRED_DEPS (list of dependencies normally optional that should be treated as required) and OPTIONAL_DEPS (list of dependencies normally required that should be optional). The main use case is to force certain optional deps to be required for your studio, to be sure that missing deps are a full build break, and not a successful build that silently lacks features you need. #2507
• Build: Fix exported config file, it was not ensuring that the Imath headers properly ended up in the config include path. #2515
• Build: Ensure compatibility and clean builds with clang 10. #2518
• Build: All the build_foo.bash helper scripts now use set -ex to ensure that if any individual commands in the script fails, the whole thing will exit with a failure. #2520
• Build correctly against the current master branch of OpenColorIO (previously we were only testing and properly building against the 1.1 release). #2530
• Added Strutil::upper() and lower() functions. #2525
• ParamValueList enhancement: new find_pv() method that is similar to find() but returns a pointer rather than an iterator and nullptr if the attribute is not found. #2527
• Add get_indexed() method to ParamValueList and AttrDelegate. #2526

Release 2.1.12 (2 Mar 2020) -- compared to 2.1.11

• Fix: plugin.h getsym() didn't pass along its report_error param. #2465
• Fix: ImageBuf::getchannel() did not honor its wrap parameter. #2465
• Fix: ImageSpec::erase_attribute() did not honor its searchtype param. #2465
• Fix: IBA::reorient() and IBA::computePixelsHashSHA1() did not honor their nthreads parameter. #2465.
• IBA::resample() now uses the clamp wrap mode to avoid black fringing and match the behavior of resize(). #2481
• Fix: ImageBuf::get_pixels() did not honor the stride parameters. #2487.
• fmath.h perf improvements: clamp() is 2x faster; madd() is improved especially on platforms without fma hardware; perf improvements in fast_sin, fast_cos; new safe_fmod is faster than std::fmod, new fast_neg is faster than simple negation in many cases, if you don't care that -(0.0) is 0.0 (rather than a true -0.0). #2491 #2492 #2494
• strutil: New function: concat(). #2478
• Build: un-embed the 'fmt' headers, instead auto-download if not found. #2439
• Build: Protect against certain compiler preprocessor errors for user programs that include strutil.h but also include fmt on its own. #2498.

Release 2.1.11 (1 Feb 2020) -- compared to 2.1.10

• Python bindings for ParamValueList.attribute(), when being passed attributes containing multiple values, now can have those values passed as Python lists and numpy arrays (previously they had to be tuples). #2437
• OpenEXR support is extended to handle float vector metadata. #2459
• Developer goody: simd.h vfloat3 has added a normalize(), length(), and length2() methods, to more closely match the syntax of Imath::Vec3f. #2437
• Internals: changed a lot of assertions to only happen in debug build mode, and changed a lot that happen in release builds to only print the error but not force a termination. #2435
• simd.h fix errors in vbool == and !=. #2463
• Make sure the embedded 'farmhash' implementation is completely hidden behind proper namespaces. #2473
• Many docs fixes.

Release 2.1.10.1 (10 Jan 2020)

• Automatically detect the need to link against libatomic (fixes build on some less common platforms, should not affect Windows, MacOS, or Linux on x86/x86_64 users). #2450 #2455
• Fixes to unordered_map_concurrent.h that affect some users who it for things other than OIIO per se (recent changes to the internals broke its use for the default underlying std::unordered_map). #2454
• Bump the minimum pybind11 version that we auto-download, and also be sure to auto-download if pybind11 is found on the system already but is not an adequately new version. #2453
• If libsquish is found on the system at build time, use it, rather than the "embedded" copy. This can improve build times of OIIO, and also helps us comply with Debian packaging rules that forbid using embedded versions of other Debian packages that can be used as simple dependencies. #2451
• Fixes to formatting of man page generation (resolves warnings on Debian build process).

Release 2.1.10 (1 Jan 2020) -- compared to 2.1.9

• Suppress warnings with old libraw on earlier gcc versions. #2413
• Exif read: guard better against out of range offests, fixes crashes when reading jpeg files with malformed exif blocks. #2429
• Python: add binding for missing ParamValue constructors. #2417
• oiiotool & ImageBuf better error messages (rather than mysterious crash) for certain out of memory conditions. #2414
• oiiotool --create and --pattern take a new optional parameter: :type=name that overrides the default behavior of allocating all internal buffers as float. #2414
• Lots of typo fixes in docs, comments, and error messages. #2438
• Fix broken version in the built openimageio.pc PkgConfig file. #2441
• Fix typo in build script that caused it to fail to set the right symbol definition when building static libs. #2442.
• More robust OIIO_PRETTY_FUNCTION definition. #2413
• Better fallback for OIIO_ALIGN, rely on C++11. #2412
• Docs: fix some II and IO chapter examples that used old open() API.
• Build: bump default version of pybind11 to 2.4.3. #2436
• Add ImageBuf::setpixel() methods that use cspan instead of ptr/len. #2443
• Fixes to cmake config generation. #2448

Release 2.1 (8 Dec 2019) -- compared to 2.0

New minimum dependencies:

• CMake minimum is now 3.12. #2348 (2.1.5)

Major new features and performance improvements:

• Support for HEIC/HEIF images. HEIC is the still-image sibling of HEVC (a.k.a. H.265), and compresses to about half the size of JPEG but with higher visual quality. #2160 #2188 (2.1.0)
• oiiotool new commands: -evaloff -evalon --metamerge --originoffset
• ImageCache/TextureSystem improved perf of the tile and file caches under heavy thread contention. In the context of a renderer, we have seen improvements of around 7% in overall render time, averaged across a suite of typical production scenes. #2314, #2316 (2.1.3) #2381 #2407 (2.1.8)
• Fix huge DPX reading performance regression. Technically this is a bug fix that restores performance we once had, but it's a huge speedup. #2333 (2.1.4)
• Reading individual frames from very-multi-image files (movie files) has been greatly sped up (10x or more). #2345 (2.1.4)

Public API changes:

• ImageSpec new methods getattribute() and getattributetype(). #2204 (2.1.1)

• ImageSpec and ParamValueList now support operator ["name"] as a way to set and retrieve attributes. For example,

  myimagespec["compression"] = "zip";
  myimagespec["PixelAspectRatio"] = 1.0f;
  int dither = myimagespec["oiio:dither"].get<int>();
  std::string cs = myimagespec["colorspace"];
  

  See the documentation about "Attribute Delegates" for more information, or the new header attrdelegate.h. #2204 (2.1.1) #2297 (2.1.3)

• ImageSpec::find_attribute now will retrieve "datawindow" and "displaywindow" (type int[4] for images int[6] for volumes) giving the OpenEXR-like bounds even though there is no such named metadata for OIIO (the results will assembled from x, y, width, height, etc.). #2110 (2.1.0/2.0.4)

• "Compression" names (where applicable) can now have the quality appended to the name (e.g., "jpeg:85") instead of requiring quality to be passed as a separate piece of metadata. #2111 (2.1.0/2.0.5)

• Python: define __version__ for the module. #2096 (2.1.0/2.0.4)

• Python error reporting for ImageOutput and ImageBuf.set_pixels involving transferring pixel arrays have changed from throwing exceptions to reporting errors through the usual OIIO error return codes and queries. #2127 (2.1.0/2.0.5)

• New shell environment variable OPENIMAGEIO_OPTIONS can now be used to set global OIIO::attribute() settings upon startup (comma separated name=value syntax). #2128 (2.1.0/2.0.5)

• ImageInput open-with-config new attribute "missingcolor" can supply a value for missing tiles or scanlines in a file in lieu of treating it as an error (for example, how OpenEXR allows missing tiles, or when reading an incompletely-written image file). A new global OIIO::attribute() setting (same name) also accomplishes the same thing for all files read. Note that this is only advisory, and not all file times are able to do this (OpenEXR is the main one of interest, so that works). #2129 (2.1.0/2.0.5)

• ImageCache::invalidate() and TextureSystem::invalidate() now take an optional force parameter (default: true) that if false, will only invalidate a file if it has been updated on disk since it was first opened. #2133, #2166 (2.1.0/2.0.5)

• New filter name "nuke-lanczos6" matches the "lanczos6" filter from Nuke. In reality, it's identical to our "lanczos3", but the name alias is supposed to make it more clear which one to use to match Nuke, which uses a different nomenclature (our "3" is radius, their "6" is full width). #2136 (2.1.0/2.0.5)

• New helper functions in typedesc.h: tostring() converts nearly any TypeDesc-described data to a readable string, convert_type() does data type conversions as instructed by TypeDesc's. #2204 (2.1.1)

• ImageBuf:

  • Construction from an ImageSpec now takes an optional zero parameter that directly controls whether the new ImageBuf should have its buffer zeroed out or left uninitialized. #2237 (2.1.2)
  • set_write_format() method has a new flavor that takes a cspan<TypeDesc> that can supply per-channel data types. #2239 (2.1.1)

• ColorConfig:

  • Added getColorSpaceFamilyByName(), getColorSpaceNames(), getLookNames(), getDisplayNames(), getDefaultDisplayName(), getViewNames(), getDefaultViewName(). #2248 (2.1.2)
  • Added Python bindings for ColorConfig. #2248 (2.1.2)

• Formal version numbers are now four parts: MAJOR.MINOR.PATCH.TWEAK. #2313,#2319 (2.1.3)

• ImageInput now sets "oiio:subimages" attribute to an int representing the number of subimages in a multi-image file -- if known from reading just the header. A positive value can be relied upon (including 1), but a value of 0 or no such metadata does not necessarily mean there are not multiple subimages, it just means it could not be known from inexpensively reading only the header. #2344 (2.1.4)

• The imagesize_t and stride_t values now have revised definitions. It should be fully API/ABI compatible (at least for 64 bit systems), but is a simpler, more modern, more platform-independent definition. #2351 (2.1.5)

• DeepData has been altered to make pixel indices and total counts int64_t rather than int, in order to be safe for very large images that have > 2 Gpixels. #2363 (2.1.5)

• On OSX, we now expect non-embedded plugins to follow the convention of naming runtime-loaded modules foo.imageio.so (just like on Linux), whereas we previously used the convention of foo.imageio.dylib. Turns out that dylib is supposed to be only for shared libraries, not runtime loadable modules. #2376 (2.1.6)

Fixes and feature enhancements:

• oiiotool:
  • New -evaloff and -evalon lets you disable and enable the expression substitution for regions of arguments (for example, if you have an input image filename that contains {} brace characters that you want interpreted literally, not evaluated as an expression). #2100 (2.1.0/2.0.4)
  • --dumpdata has more intelligible output for uint8 images. #2124 (2.1.0/2.0.4)
  • Fixed but that could prevent -iconvert oiio:UnassociatedAlpha 1 from correctly propagating to the input reader. #2172 (2.1.0/2.0.6)
  • -o:all=1 (which outputs all subimages to separate files) fixed a crash that would occur if any of the subimages were 0x0 (it could happen; now it just skips outputting those subimages). #2171 (2.1.0)
  • Improved support of files with multiple subimages: Several commands honored -a but did not respect individual allsubimages= modifiers (--ch, --sattrib, --attrib, --caption, --clear-keywords, --iscolorspace, --orientation, --clamp, -fixnan); Several commands always worked on all subimages, but now properly respect -a and allsubimages= (--origin, --fullpixels, --croptofull, --trim); Several commands were totally unaware of subimages, but now are so and respect -a and allsubimages= (--crop, --fullsize, --zover, --fill, --resize, --resample). #2202 #2219, #2242 (2.1.1, 2.1.2)
  • --ociodisplay: empty display or view names imply using the default display or view. #2273 (2.0.10/2.1.3)
  • --metamerge option causes binary image operations to try to "merge" the metadata of their inputs, rather than simply copy the metadata from the first input and ignore the others. #2311 (2.1.3)
  • --colormap now supports a new "turbo" color map option. #2320 (2.1.4)
  • Expression evaluation has been extended to support operators // for integer division (whereas / is floating point division), and % for integer modulus. #2362 (2.1.5)
  • New --originoffset resets the data window origin relative to its previous value (versus the existing --origin that sets it absolutely). #2369 (2.1.5)
  • --paste has two new optional modifiers: :all=1 pastes the entire stack of images together (versus the default of just pasting the top two images on the stack), and :mergeroi=1 causes the result to have the merged data window of all inputs, instead of the foreground image clipping against the boundary of the background image data. #2369 (2.1.5)
  • --paste now works with deep images. #2369 (2.1.5)
  • --paste semantics have changed: the meaning of pasting FG into BG at (x,y) now means that the (0,0) origin of FG ends up at (x,y), whereas before it placed the corner of FG's data window at (x,y). This will not change behavior for ordinary images where FG's data window is (0,0), but it makes behavior more sensible for "cropped" or "shrink-wrapped" FG images that have non-zero data window origin. #2369 (2.1.5)
  • paste() is now multithreaded and therefore much faster. #2369 (2.1.5)
  • --ociotransform no longer issues an error message when no valid OCIO configuration is found (because it's not needed for this operation). #2371 (2.1.5)
  • --compare would fail to notice differences in deep images where the corresponding pixels had differing numbers of samples. #2381 (2.1.8)
• ImageBuf/ImageBufAlgo:
  • IBA::channel_append() previously always forced its result to be float, if it wasn't previously initialized. Now it uses the usual type-merging logic, making the result the "widest" type of the inputs. #2095 (2.1.0/2.0.4)
  • IBA resize(), fit(), and resample() are no longer restricted to source and destination images having the same number of channels. #2125 (2.1.0/2.0.5)
  • Improve numerical precision of the unpremult/premult part of certain color transformations. #2164 (2.1.0)
  • ImageBuf::read() now properly forwards the "progress" parameters to any underlying call to read_image. #2196 (2.1.1)
  • The OIIO_DISPATCH_COMMON_TYPES2/3 macros used internally by many IBA functions have been expanded to handle a few more cases "natively" without conversion to/from float. This may make a few cases of odd data type combinations have higher precision. #2203 (2.0.8/2.1.1)
  • IBA resize() fix precision issues for 'double' images. #2211 (2.0.8/2.1.1)
  • IBA::ociodisplay(): empty display or view names imply using the default display or view. #2273 (2.0.10/2.1.3)
  • IBA::fixNonFinite(): fixed impicit float/double casts to half. #2301 (2.0.10/2.1.3)
  • IBA::color_map(): now supports a new "turbo" color map option. #2320 (2.1.4)
  • IBA::paste() now works with deep images. #2369 (2.1.5)
  • paste semantics have changed: the meaning of pasting FG into BG at (x,y) now means that the (0,0) origin of FG ends up at (x,y), whereas before it placed the corner of FG's data window at (x,y). This will not change behavior for ordinary images where FG's data window is (0,0), but it makes behavior more sensible for "cropped" or "shrink-wrapped" FG images that have non-zero data window origin. #2369 (2.1.5)
  • paste() is now multithreaded and therefore much faster. #2369 (2.1.5)
  • ociotransform() no longer issues an error message when no valid OCIO configuration is found (because it's not needed for this operation). #2371 (2.1.5)
  • Python ociotransform and ociolook mixed up the names and orders of the inverse and unpremult params, making it so that you couldn't properly specify the inverse. #2371 (2.1.5)
  • IBA::compare() would fail to notice differences in deep images where the corresponding pixels had differing numbers of samples. #2381 (2.1.8)
• ImageInput read_image/scanline/tile fixed subtle bugs for certain combination of strides and channel subset reads. #2108 (2.1.0/2.0.4)
• ImageCache / TextureSystem / maketx:
  • More specific error message when tile reads appear to be due to the file having changed or been overwritten on disk since it was first opened. #2115 (2.1.0/2.0.4)
  • maketx: the -u (update mode) is slightly less conservative now, no longer forcing a rebuild of the texture just because the file uses a different relative directory path than last time. #2109 (2.1.0/2.0.4)
  • Protection against certain divide-by-zero errors when using very blurry latong environment map lookups. #2121 (2.1.0/2.0.5)
  • maketx -u is smarter about which textures to avoid re-making because they are repeats of earlier commands. #2140 (2.1.0/2.05)
  • Fix possible maketx crash on Windows due to a stack overflow within MSVS's implementation of std::regex_replace! #2173 (2.1.0/2.0.6)
  • TS: New attribute "max_mip_res" limits filtered texture access to MIP levels that are no higher than this resolution in any dimension. The default is 1<<30, meaning no effective limit. #2174 (2.1.1)
  • Stats now count the number of TS::get_texture_info/IC::get_image_info calls, like it did before for texture, etc. #2223 (2.1.1)
  • TS::environment() can resolve subimage by name, as we do for texture() and texture3d(). #2263
  • Improvements to error message propagation. (2.1.3)
  • Avoid creating a new thread info struct while resolving udims. #2318 (2.1.4)
  • Work around bug in OpenEXR, where dwaa/dwab compression can crash when used on 1-channel tiled images with a tile size < 16. This can crop up for MIP-maps (high levels where rez < 16), so we detect this case and switch automatically to "zip" compression. #2378 (2.1.6)
  • When converting images to texture (via maketx or IBA::make_texture), correctly handle color space conversions for greyscale images. #2400 (2.1.8)
• iv viewer:
  • Image info window now sorts the metadata, in the same manner as iinfo -v or oiiotool -info -v. #2159 (2.1.0/2.0.5)
• All command line utilities, when run with just --help, will exit with return code 0. In other words, utility --help is not an error. #2364 (2.1.5) #2383 (2.1.8)
• Python bindings:
  • Fix inability for Python to set timecode attributes (specifically, it was trouble setting ImageSpec attributes that were unsigned int arrays). #2279 (2.0.9/2.1.3)
• Improved performance for ustring creation and lookup. #2315 (2.1.3)
• BMP:
  • Fix bugs related to files with very high resolution (mostly 32 bit int overflow issues and care to use 64 bit fseeks). Also speed up reading and writing very large files. #2404 (2.1.8)
• DPX:
  • Now recognizes the new transfer/colorimetric code for ADX. #2119 (2.1.0/2.0.4)
  • Fix potential crash when file open fails. #2186 (2.0.7/2.1.1)
  • Support for reading and writing 1-channel (luma, etc.) images. #2294 (2.0.10/2.1.3)
  • Fix huge DPX reading performance regression. #2333 (2.1.4)
  • Fix bugs related to int32 math that would lead to incorrect behavior in very high-resolution files. #2396 (2.1.3)
• ffmpeg/Movie files:
  • Reading individual frames from very-multi-image files (movie files) has been greatly sped up (10x or more). #2345 (2.1.4)
  • Support for reading movie files that (a) contain alpha channels, and (b) have bit depths > 8 bits per channel. Previously, such files would be read, but would be presented to the app as a 3-channel 8 bit/channel RGB. #2349 (2.1.5)
• FITS:
  • Fix 16 and 32 bit int pixels which FITS spec says are signed, but we were treating as unsigned. #2178 (2.1.0)
• HDR/RGBE:
  • Fix bugs related to files with very high resolution (mostly 32 bit int overflow issues and care to use 64 bit fseek). Also speed up reading and writing very large files. #2406 (2.1.8)
• IFF
  • Detect and error requests to open files for writing with resolutions too high to be properly supported by IFF files. #2397 (2.1.8)
  • Improve error messages when a file can't be opened. #2398 (2.1.8)
• JPEG:
  • Read-from-memory is now supported via IOProxy use. #2180. (2.1.1)
• JPEG-2000:
  • Disable JPEG-2000 support for the (rare) combination of an older OpenJPEG 1.x and EMBEDPLUGINS=0 mode, which was buggy. The solution if you really need EMBEDPLUGINS and JPEG-2000 support is to please use OpenJPEG >= 2.0. #2183. (2.0.7/2.1.1)
• OpenEXR:
  • Avoid some OpenEXR/libIlmImf internal errors with DWA compression by switching to zip for single channel images with certain small tile sizes. #2147 (2.1.0/2.0.5)
  • Suppress empty string subimage name (fixes a problem with certain V-Ray written multi-part exr images). #2190 (2.1.1/2.0.7)
  • Fixed bug that broke th ability to specify compression of multipart OpenEXR files. #2252 (2.1.2)
• PNG:
  • More careful catching and reporting errors and corrupt PNG files. #2167 (2.1.0/2.0.6)
  • IOProxy reading is now supported. #2180. (2.1.1)
• PSD:
  • When reading PSD files with multiple PhotoShop "layers", properly set ImageSpec x, y to the image plane offset (upper left corner) of the layer, and set and metadata "oiio:subimagename" to the layer name. #2170 (2.1.0)
• RAW:
  • Clarification about color spaces: The open-with-config hint "raw:ColorSpace" is more careful about color primaries versus transfer curve. Asking for "sRGB" (which is the default) gives you true sRGB -- both color primaries and transfer. Asking for "linear" gives you linear transfer with sRGB/Rec709 primaries. The default is true sRGB, because it will behave just like JPEG. #2260 (2.1.2)
  • Added "raw:half_size" and "raw:user_mul" configuration attributes. #2307 (2.1.3)
• RLA:
  • Improved logic for determining the single best data type to report for all channels. #2282 (2.1.3)
• SGI:
  • Fix bugs when writing extremely high resolution images, due to internal 32 bit arithmetic on file offsets. #2402 (2.1.8)
  • Speed up reading and writing of SGI files. #2402 (2.1.8)
• Targa:
  • Put in checks to detect and error requests to write Targa with resolutions too high to be supported by the format. #2405 (2.1.8)
• TIFF:
  • Fix problems with JPEG compression in some cases. #2117 (2.1.0/2.0.4)
  • Fix error where reading just a subset of channels, if that subset did not include the alpha channel but the image was "unassociated alpha", the attempt to automatically associate (i.e. "premultiply" the alpha) upon read would get bogus values because the alpha channel was not actually read. Now in this case it will not do the premultiplication. So if you are purposely reading RGB only from an RGBA file that is specifically "unassociated alpha", beware that you will not get the automatic premultiplication. #2122 (2.1.0/2.0.4)
  • More careful check and error reporting when user tries to request writing to a TIFF file mixed channel data types (which is not supported by the underlying libtiff). #2112 (2.1.0/2.0.5)
  • Fix crash reading certain old nconvert-written TIFF files. #2207 (2.0.8/2.1.1)
  • Fix bugs when reading TIFF "cmyk" files. #2292. (2.0.10/2.1.3)
  • Correctly handle read and write of 6, 14, and 24 bit per sample images. #2296 (2.1.3)
  • Fix potential deadlock in TIFF I/O: minor flaw with threadpool method #2327 (2.1.4)
• WebP:
  • Fix bug that gave totally incorrect image read for webp images that had a smaller width than height. #2120 (2.1.0/2.0.4)
• zfile:
  • Put in checks to detect and error requests to write zfiles with resolutions too high to be supported by the format. #2403 (2.1.8)
• Fix potential threadpool deadlock issue that could happen if you were (among possibly other things?) simultaneously calling make_texture from multiple application threads. #2132 (2.1.0/2.0.4)
• ImageInput/ImageOutput create() now properly lets you specify the type for reader/writer from the format name itself (versus just the extension, for example "openexr" versus "exr"). #2185 (2.1.1)
• Make all the various "could not open" messages across the writers use the same phrasing. #2189 (2.1.1)
• Better care in some image readers/writers to avoid errors stemming from integer overflow when compting the size of large images. #2232 (2.1.2)

Build/test system improvements and platform ports:

• Major overhaul of the CMake build system now that our CMake minimum is 3.12. #2348 #2352 #2357 #2360 #2368 #2370 #2372 #2373 (2.1.5) #2392 (2.1.8) Highlights:
  • All optional dependencies (e.g. "Pkg") now can be disabled (even if found) with cmake -DUSE_PKG=0 or environment variable USE_PKG=0. Previously, some packages supported this, others did not.
  • All dependencies can be given find hints via -DPkg_ROOT=path or by setting environment variable Pkg_ROOT=path. Previously, some did, some didn't, and the ones that did had totally inconsistent names for the path hint variable (PKG_HOME, PKG_ROOT_DIR, PKG_PATH, etc).
  • Nice color coded status messages making it much more clear which dependencies were found, which were not, which were disabled.
  • Use standard BUILD_SHARED_LIBS to control shared vs static libraries, replacing the old nonstandard BUILDSTATIC name.
  • Use correct PUBLIC/PRIVATE marks with target_link_libraries and target_include_directories, and rely on cmake properly understanding the transitive dependencies.
  • CMAKE_DEBUG_POSTFIX adds an optional suffix to debug libraries.
  • CMAKE_CXX_STANDARD to control C++ standard (instead of our nonstandard USE_CPP).
  • CXX_VISIBILITY_PRESET controls symbol visibility defaults now, not our nonstandard HIDE_SYMBOLS. And the default is to keep everything hidden that is not part of the public API.
  • At config time, ENABLE_<name>=0 (either as a CMake variable or an env variable) can be used to disable any individual file format or command line utility. E.g., cmake -DENABLE_PNG=0 -DENABLE_oiiotool=0 This makes it easier to greatly reduce build time if you are 100% sure there are formats or components you don't want or need.
  • Config based install and usage.
• Deprecate "missingmath.h". What little of it is still needed (it mostly addressed shortcomings of old MSVS releases) is now in fmath.h. #2086
• Remove "osdep.h" header that was no longer needed. #2097
• Appveyor scripts have been overhauled and simplified by relying on vcpkg to build dependencies. #2113 (2.1.0/2.0.4)
• Detect and error if builder is trying to use a pybind11 that's too old. #2144 (2.1.0/2.0.5)
• New CMake build-time option OIIO_LIBNAME_SUFFIX (default: empty) lets you append an optional name to the libraries produced (to disambiguate two builds at the same facility or distro, much like you could do before for symbols with custom namespaces). #2148 (2.1.0)
• On MacOS 10.14 Mojave, fix warnings during iv compiler about OpenGL being deprecated in future releases. #2151 (2.1.0/2.0.5)
• At build time, the Python version used can be controlled by setting the environment variable $OIIO_PYTHON_VERSION, which if set will initialize the default value of the CMake variable PYTHON_VERSION. #2161 (2.0.5/2.1.0)
• On non-Windows systems, the build now generates a PkgConfig file, installed at CMAKE_INSTALL_PREFIX/lib/pkgconfig/OpenImageIO.pc. #2158 (2.0.5/2.1.0)
• A new unit test has been backported from master, which tries to perform a series of read/write tests on every file format. In particular, this tests certain error conditions, like files not existing, or the directory not being writable, etc. #2181, #2189 (2.0.8/2.1.1)
• Support for CI tests on CircleCI. #2194 (2.1.1) Retired in #2389 (2.1.8).
• New build-time flag USE_WEBP=0 can be used to disable building WebP format support even on platforms where webp libraries are found. #2200 (2.1.1)
• Fix compiler warnings on Windows. #2209 #2213 #2214 #2392
• Crashes in the command line utilities now attempt to print a stack trace to aid in debugging (but only if OIIO is built with Boost >= 1.65, because it relies on the Boost stacktrace library). #2229 (2.0.8/2.1.1)
• Add gcc9 to Travis tet matrix and fix gcc9 related warnings. #2235 (2.1.2)
• VDB reader pulled in the TBB libraries using the wrong CMake variable. #2274 (2.1.3)
• The embedded fmt implementation has been updated to fix windows warnings. #2280 (2.1.3)
• Improvements for finding certain new Boost versions. #2293 (2.0.10/2.1.3)
• Build fixes for MinGW. #2304, #2308 (2.0.10/2.1.3)
• libraw: Fixes to make it build properly against some changes in the libraw development master. #2306 (2.1.3)
• Use GitHub Actions CI. Eliminate Appveyor and some Travis tests. #2334 (2.1.4) #2356 (2.1.5) #2395 (2.1.8)
• Updated and improved finding of OpenEXR and build_openexr.bash script that we use for CI. #2343 (2.1.4)
• Upgrade the pybind11 version that we auto-install when not found (to 2.4.2), and add logic to detect the presence of some pybind11 versions that are known to be (buggily) incompatible with C++11. #2347 (2.1.5)
• Fix errors in very new MSVS versions where it identified a suspicious practice of ImageBuf's use of a unique_ptr of an undefined type. Jump through some hoops to make that legal. #2350 (2.1.5)
• All Python scripts in the tests have been modified as needed to make them correct for both Python 2.7 and 3.x. #2355, #2358 (2.1.5)
• Tests are now safe to run in parallel and in unspecified order. Running with env variable CTEST_PARALLEL_LEVEL=[something more than 1] greatly speeds up the full testsuite on multi-core machines. #2365 (2.1.5)
• Bump robin map version to latest release (v0.6.2) #2401 (2.1.8)
• Fix compiler warnings in ustring.h when _LIBCPP_VERSION is not defined. #2415 (2.1.8.1)
• Bump fmt library to v6.1.0. #2423 (2.1.8.1)

Developer goodies / internals:

• argparse.h:
  • Add unit tests. #2192 (2.1.1)
  • Add "%1" which is like "%*" but its list receives only arguments that come before any other dash-led arguments. #2192 (2.1.1)
  • Allow specifiers such as "%d:WIDTH" the part before the colon is the type specifier, the part after the colon is the name of the parameter for documentation purposes. #2312 (2.1.3)
• attrdelegate.h:
  • New header implements "attribute delegates." (Read header for details) #2204 (2.1.1)
• dassert.h:
  • Spruce up assertion macros: more uniform wording, and use pretty function printing to show what function the failure was in. #2262
  • The new preferred assertion macros are OIIO_ASSERT and OIIO_DASSERT. The OIIO_ASSERT always tests and prints an error message if the test fails, but now only aborts when compiled without NDEBUG defined (i.e. no abort for release builds), whereas OIIO_DASSERT is for debug mode only and does nothing at all (not even perform the test) in release mode. These names and behaviors are preferred over the old ASSERT and DASSERT, though those deprecated names will continue for at least another major release. #2411 (2.1.8.1)
• filesystem.h:
  • Change many filesystem calls to take string_view arguments. #2388 (2.1.8)
  • New fseek() and ftell() that always use 64 bit offsets to be safe for very large files. #2399 (2.1.8)
• fmath.h:
  • safe_mod() does integer modulus but protects against mod-by-zero exceptions. #2121 (2.1.0/2.0.5)
  • pow2roundup/pow2rounddown have been renamed ceil2/floor2 to reflect future C++20 standard. The old names still work, so it's a fully back compatible change. #2199 (2.0.8/2.1.1)
  • To match C++20 notation, use rotl() template innstead of separate rotl32/rotl64 functions. #2299, #2309 (2.1.3)
• platform.h:
  • New OIIO_RETURNS_NONNULL macro implements an attribute that marks a function that returns a pointer as guaranteeing that it's never NULL. #2150 (2.1.0/2.0.5)
• SHA1.h:
  • Upgraded this embedded code from version 1.8 (2008) to the newest release, 2.1 (2012). This fixes some Windows warnings. #2342 (2.1.4)
• simd.h:
  • Added vec4 * matrix44 multiplication. #2165 (2.1.0/2.0.6)
  • Guard against shenanigans when Xlib.h having been included and #defineing True and False. #2272 (2.0.9/2.1.3)
• strutil.h:
  • Added excise_string_after_head(). #2173 (2.1.0/2.0.6)
  • Fixed incorrect return type of stof(). #2254 (2.1.2)
  • Added remove_trailing_whitespace() and trim_whitespace(). #2298 (2.1.3)
  • Strutil::wordwrap() now lets you specify the separation characters more flexibly (rather than being hard-coded to spaces as separators). #2116 (2.1.0/2.0.4)
  • Strutil::parse_while(). #2139 (2.1.0/2.0.5)
  • Added a variety of join() that allows you to set the number of items joined, truncating or padding with default values as needed. #2408 (2.1.8)
  • Fix join to produce a joined string of float-like values with locale-independent formatting. #2408 (2.1.8)
  • Fix vsnprintf to be locale independent. #2410 (2.1.8)
  • New lstrip() and rstrip() are just like the existing strip(), but operate only on the beginning/left side or ending/right side of the string, respectively. #2409 (2.1.8)
• string_view.h:
  • string_view now adds an optional pos parameter to the find_first_of / find_last_of family of methods. #2114 (2.1.0/2.0.4)
• sysutil.h:
  • Added stacktrace() and setup_crash_stacktrace(). (Only functional if OIIO is built with Boost >= 1.65, because it relies on the Boost stacktrace library). #2229 (2.0.8/2.1.1)
• unittest.h:
  • Add OIIO_CHECK_IMAGEBUF_STATUS() test macro. #2394 (2.1.8)
• unordered_map_concurrent.h:
  • Performance improvement by avoiding redundant hashing of keys, and improving the speed and properties of the hash function. #2313, #2316 (2.1.3)
• ustring.h:
  • Bug fix in ustring::compare(string_view), in cases where the string_view was longer than the ustring, but had the same character sequence up to the length of the ustring. #2283 (2.0.10/2.1.3)
• Wide use of declaring methods noexcept when we want to promise that they won't throw exceptions. #2156, #2243 (2.1.0, 2.1.2)
• Changed all (we think) internal string formatting that expects printf formatting notation to use the errorf/sprintf style calls, in anticipation of the error/format (no trailing -f) calls to eventually follow the std::format/python formatting notation. #2393 (2.1.8)

Notable documentation changes:

• The whole documentation system has been overhauled. The main docs have been converted from LaTeX to Sphinx (using Doxygen and Breathe) for beautiful HTML as well as PDF docs and automatic hosting on https://openimageio.readthedocs.io #2247,2250,2253,2255,2268,2265,2270
• Copyright notices have been changed for clarity and conformance with SPDX conventions. #2264
• New GitHub issue templates, making separate issue types for bug reports, feature requests, build problems, and questions. #2271,#2346

Release 2.0.13 (1 Dec 2019) -- compared to 2.0.12

• Bug fix in deep image compare (IBA::compare() or oiiotool --compare) would fail to notice differences in deep images where the corresponding pixels had differing numbers of samples. #2381 (2.1.8/2.0.13)
• DPX: Fix bugs related to int32 math that would lead to incorrect behavior in very high-resolution files. #2396 (2.1.3/2.0.13)
• When converting images to texture (via maketx or IBA::make_texture), correctly handle color space conversions for greyscale images. #2400 (2.1.8/2.0.13)
• Build: suppress warnings with libraw for certain gcc versions.
• Build: Fix compiler warnings in ustring.h when _LIBCPP_VERSION is not defined. #2415 (2.1.8.1/2.0.13)
• filesystem.h: New fseek() and ftell() that always use 64 bit offsets to be safe for very large files. #2399 (2.1.8/2.0.13)
• Strutil::parse_string() - fix bugs that would fail for escaped quotes within the string. #2386 (2.1.8/2.0.13)
• Strutil::join() added a variety that allows you to set the number of items joined, truncating or padding with default values as needed. #2408 (2.1.8/2.0.13)
• New Strutil::lstrip() and rstrip() are just like the existing strip(), but operate only on the beginning/left side or ending/right side of the string, respectively. #2409 (2.1.8/2.0.13)

Release 2.0.12 (1 Nov, 2019) -- compared to 2.0.11

• Fix compiler warnings on some platform. #2375
• Work around bug in OpenEXR, where dwaa/dwab compression can crash when used on 1-channel tiled images with a tile size < 16. This can crop up for MIP-maps (high levels where rez < 16), so we detect this case and switch automatically to "zip" compression. #2378

Release 2.0.11 (1 Oct, 2019) -- compared to 2.0.10

• Fixes to build against LibRaw master. #2306
• Fix DPX reading performance regression. #2333
• Guard against buggy pybind11 versions. #2347
• Fixes for safe Cuda compilation of invert<> in fmath.h. #2197

Release 2.0.10 (1 Aug, 2019) -- compared to 2.0.9

• ColorConfig improvements: (a) new getColorSpaceFamilyByName(); (b) new methods to return the list of all color spaces, looks, displays, or views for a display; (c) all of ColorConfig now exposed to Python. #2248
• IBA::ociodisplay() and oiiotool --ociodisplay: empty display or view names imply using the default display or view. #2273
• Bug fix in ustring::compare(string_view), in cases where the string_view was longer than the ustring, but had the same character sequence up to the length of the ustring. #2283
• oiiotool --stats: Fixed bug where -iconfig hints were not being applied to the file as it was opened to compute the stats. #2288
• Bug fix: IBA::computePixelStats() was not properly controlling the number of threads with the nthreads parameter. #2289
• Bug fix when reading TIFF bugs: In cases where the reader needed to close and re-open the file silently (it could happen for certain scanline traversal patterns), the re-open was not properly honorig any previous "rawcolor" hints from the original open. #2285
• Nuke txWriter updates that expose additional make_texture controls. #2290
• Build system: Improvements for finding certain new Boost versions. #2293
• Build system: Improvements finding OpenEXR installation.
• Fix bugs when reading TIFF "cmyk" files. #2292.
• DPX: support for reading and writing 1-channel (luma, etc.) DPX images. #2294
• IBA::fixNonFinite(): fixed impicit float/double casts to half. #2301
• Build fixes for MinGW. #2304

Release 2.0.9 (4 Jul, 2019) -- compared to 2.0.8

• RAW: Clarification about color spaces: The open-with-config hint "raw:ColorSpace" is more careful about color primaries versus transfer curve. Asking for "sRGB" (which is the default) gives you true sRGB -- both color primaries and transfer. Asking for "linear" gives you linear transfer with sRGB/Rec709 primaries. The default is true sRGB, because it will behave just like JPEG. #2260 (2.1.2)
• Improved oiiotool support of files with multiple subimages: Several commands honored -a but did not respect individual allsubimages= modifiers (--ch, --sattrib, --attrib, --caption, --clear-keywords, --iscolorspace, --orientation, --clamp, -fixnan); Several commands always worked on all subimages, but now properly respect -a and allsubimages= (--origin, --fullpixels, --croptofull, --trim); Several commands were totally unaware of subimages, but now are so and respect -a and allsubimages= (--crop, --fullsize, --zover, --fill, --resize, --resample). #2202 #2219, #2242
• Fix broken ability to specify compression of multipart exr files. #2252
• Fix Strutil::stof() return type error and other windows warnings. #2254
• IBA::colortmatrixtransform() and oiiotool --ccmatrix allow you to perform a matrix-based color space transformation. #2168
• Guard simd.h against shenanigans when Xlib.h having been included and #defineing True and False. #2272
• RAW: Clarification about color spaces: The open-with-config hint "raw:ColorSpace" is more careful about color primaries versus transfer curve. Asking for "sRGB" (which is the default) gives you true sRGB -- both color primaries and transfer. Asking for "linear" gives you linear transfer with sRGB/Rec709 primaries. The default is true sRGB, because it will behave just like JPEG. #2260
• Fix inability for python to set timecode attributes (specifically, it was trouble setting ImageSpec attributes that were unnsigned int arrays). #2279

Release 2.0.8 (3 May, 2019) -- compared to 2.0.7

• Fix Windows broken read of JPEG & PNG in some circumstances. #2231
• Some minor fixes to JPEG & PNG reading and file error robustness. #2187
• Fix crash reading certain old nconvert-written TIFF files. #2207
• Internals: The OIIO_DISPATCH_COMMON_TYPES2/3 macros used by many ImageBufAlgo functions have been expanded to handle a few more cases "natively" without conversion to/from float. This may make a few cases of odd data type combinations have higher precision. #2203
• ImageBufAlgo::resize() fixes precision issues for 'double' images. #2211
• Testing: A new unit test has been backported from master, which tries to perform a series of read/write tests on every file format. In partcular, this tests certain error conditions, like files not existing, or the directory not being writable, etc. #2181
• Crashes in the command line utilities now attempt to print a stack trace to aid in debugging (but only if OIIO is built with Boost >= 1.65, because it relies on the Boost stacktrace library). #2229
• Dev goodies: fmath.h's powwroundup/pow2rounddown have been renamed ceil2/floor2 to reflect future C++ standard. The old names still work, so it's a fully back compatible change. #2199

Release 2.0.7 (1 Apr, 2019) -- compared to 2.0.6

• DPX: fix potential crash when file open fails. #2186
• EXR: Suppress empty string for subimage name (fixes a problem when reading files written by V-Ray). #2190
• Disable JPEG-2000 support for the (rare) combination of an older OpenJPEG 1.x and EMBEDPLUGINS=0 mode, which was buggy. The solution if you really need EMBEDPLUGINS and JPEG-2000 support is to please use OpenJPEG >= 2.0. #2183.
• New build flag USE_WEBP=0 can be set to 0 to force disabled support of WebP even when the webp package is found. #2200
• Bug fix: ImageInput::create(name) and ImageOutput::create(name) worked if name was a filename (such as foo.exr), or the extension (such as exr), but previously did not work if it was the name of the format (such as openexr), despite having been documented as working in that case. #2185

Release 2.0.6 (1 Mar, 2019) -- compared to 2.0.5

• PNG: more careful catching of errors and corrupt png files. #2167
• PSD: read now properly extracts layer/subimage name and data window offset coordinates. #2170
• ImageBuf: Fix bug in propagating unassociated alpha behavior request. #2172
• oiiotool -o:all=1 fix crash when outputting 0x0 subimages. #2171
• Developer goodies: simd.h ops for vec4 * mat44 multiplication. #2165
• Developer goodies: Strutil::excise_string_after_head() #2173
• Fix crashes on Windows from certain regex replacement happening as part of MakeTexture (internally avoid MSVS implementation of std::regex). #2173

Release 2.0.5 (1 Feb, 2019) -- compared to 2.0.4

• resize(), fit(), and resample() are no longer restricted to source and destination images having the same numer of channels. #2125
• Python error reporting for ImageOutput and ImageBuf.set_pixels involving transferring pixel arrays have changed from throwing exceptions to reporting errors through the usual OIIO error return codes and queries. #2127
• Protection against certain divide-by-zero errors when using very blurry latlong environment map lookups. #2121
• New shell environment variable OPENIMAGEIO_OPTIONS can now be used to set global OIIO::attribute() settings upon startup (comma separated name=value syntax). #2128
• ImageInput open-with-config new attribute "missingcolor" can supply a value for missing tiles or scanlines in a file in lieu of treating it as an error (for example, how OpenEXR allows missing tiles, or when reading an incompletely-written image file). A new global OIIO::attribute() setting (same name) also accomplishes the same thing for all files read. Note that this is only advisory, and not all file times are able to do this (OpenEXR is the main one of interest, so that works). #2129
• New filter name "nuke-lanczos6" matches the "lanczos6" filter from Nuke. In reality, it's identical to our "lanczos3", but the name alias is supposed to make it more clear which one to use to match Nuke, which uses a different nomenclature (our "3" is radius, their "6" is full width). #2136
• maketx -u is smarter about which textures to avoid re-making because they are repeats of earlier commands. #2140
• Detect/error if builder is trying to use a pybind11 that's too old. #2144
• OpenEXR: avoid some OpenEXR/libIlmImf internal errors with DWA compression by switching to zip for single channel images with certain small tile sizes. #2147
• On MacOS 10.14 Mojave, fix warnings during iv compile about OpenGL being deprecated in future releases. #2151
• iv info window now sorts the metadata. #2159
• At build time, the Python version used can be controlled by setting the environment variable $OIIO_PYTHON_VERSION, which if set will initialize the default value of the CMake variable PYTHON_VERSION. #2161 (2.0.5)
• On non-Windows systems, the build now generates a PkgConfig file, installed at CMAKE_INSTALL_PREFIX/lib/pkgconfig/OpenImageIO.pc. #2158 (2.0.5)

Release 2.0.4 (Jan 5, 2019) -- compared to 2.0.3

• Fix potential threadpool deadlock issue that could happen if you were (among possibly other things?) simultaneously calling make_texture from multiple application threads. #2132
• ImageInput read_image/scanline/tile fixed subtle bugs for certain combination of strides and channel subset reads. #2108
• TIFF: Fix problems with JPEG compression in some cases. #2117
• TIFF: Fixed error where reading just a subset of channels, if that subset did not include the alpha channel but the image was "unassociated alpha", the attempt to automatically associate (i.e. "premultiply" the alpha) upon read would get bogus values because the alpha channel was not actually read. Now in this case it will not do the premultiplication. So if you are purposely reading RGB only from an RGBA file that is specifically "unassociated alpha", beware that you will not get the automatic premultiplication. #2122
• Python: define __version__ for the module. #2096
• IBA::channel_append() previously always forced its result to be float, if it wasn't previously initialized. Now it uses the uaual type-merging logic, making the result the "widest" type of the inputs. #2095
• ImageSpec::find_attribute now will retrieve "datawindow" and "displaywindow" (type int[4] for images int[6] for volumes) giving the OpenEXR-like bounds even though there is no such named metadata for OIIO (the results will assembled from x, y, width, height, etc.). #2110
• ImageCache/TextureSystem: more specific error message when tile reads appear to be due to the file having changed or been overwritten on disk since it was first opened. #2115
• oiiotool: New -evaloff and -evalon lets you disable and enable the expression substitution for regions of arguments (for example, if you have an input image filename that contains {} brace characters that you want interpreted literally, not evaluated as an expression). #2100
• oiiotool --dumpdata has more intelligible output for uint8 images. #2124
• maketx: the -u (update mode) is slightly less conservative now, no longer forcing a rebuild of the texture just because the file uses a different relative directory path than last time. #2109
• WebP: fix bug that gave totally incorrect image read for webp images that had a smaller width than height. #2120
• Developer goodies: string_view now adds an optional pos parameter to the find_first_of/find_last_of family of methods. #2114
• Dev goodies: Strutil::wordwrap() now lets you specify the separation characters more flexibly (rather than being hard-coded to spaces as separators). #2116

Release 2.0 (Dec 1, 2018) -- compared to 1.8.x

New minimum dependencies:

• On Windows compiling with MSVS, the new minimum version is MSVS 2015.

Major new features and improvements:

• ImageInput and ImageOutput static create() and open() methods now return unique_ptr rather than raw pointers. #1934, #1945 (1.9.3).
• ImageInput improvements to thread safety and concurrency, including some new API calls (see "Public API changes" section below).
• ImageBufAlgo overhaul (both C++ and Python): Add IBA functions that return image results directly rather than passing ImageBuf references as parameters for output (the old kind of calls still exist, too, and have their uses). Also in C++, change all IBA functions that took raw pointers to per-channel colors into span<> for safety. #1961 (1.9.4)
• For some readers and writers, an "IOProxy" can be passed that customizes the I/O methods. An important use of this is to write an image "file" to memory or to read an image "file" from a memory, rather than disk. Currently, OpenEXR supports this for both reading and writing, and PNG supports it for writing. You specify a pointer to the proxy via the configuration option "oiio:ioproxy". #1931 (1.9.3)
• New Image Format support:
  • OpenVDB file read (as volume images or accessing via texture3d()). #2010,2018 (1.9.4)
  • "null" images -- null reader just returns black (or constant colored) pixels, null writer just returns. This can be used for benchmarking (to eliminate all actual file I/O time), "dry run" where you want to test without creating output files. #1778 (1.9.0), #2042 (1.9.4)
• TIFF I/O of multiple scanlines or tiles at once (or whole images, as is typical use case for oiiotool and maketx) is sped up by a large factor on modern multicore systems. We've seen 10x or more faster oiiotool performance for uint8 and uint16 TIFF files using "zip" (deflate) compression, on modern 12-16 core machines. #1853 (1.9.2)
• Major refactor of Exif metadata handling, including much more complete metadata support for RAW formats and support of camera "maker notes" for Canon cameras. #1774 (1.9.0)
• New maketx option --bumpslopes specifically for converting bump maps, saves additional channels containing slope distribution moments that can be used in shaders for "bump to roughness" calculations. #1810,#1913,2005 (1.9.2), #2044 (1.9.4)
• An official FindOpenImageIO.cmake that we invite you to use in other cmake-based projects that needs to find OIIO. #2027 (1.9.4)

Public API changes:

• Python binding overhaul The Python bindings have been reimplemented with pybind11, no longer with Boost.Python. #1801 (1.9.1) In the process (partly due to what's easy or hard in pybind11, but partly just because it caused us to revisit the python APIs), there are some minor API changes, some of which are breaking! To wit:
  • All of the functions that are passed or return blocks of pixels (such as ImageInput.read_image()) now use Numpy ndarray objects indexed as [y][x][channel] (no longer using old-style Python array.array and flattened to 1D).
  • Specilized enum type ImageInput.OpenMode has been replaced by string parameters, so for example, old ImageInput.open(filename, ImageInput.Create) is now ImageInput.open (filename, "Create")
  • Any function that previously took a parameter of type TypeDesc or TypeDesc.BASETYPE now will accept a string that signifies the type. For example, ImageBuf.set_write_format("float") is now a synonym for ImageBuf.set_write_format(oiio.TypeDesc(oiio.FLOAT)).
  • For several color conversion functions, parameter names were changed from "from" to "fromspace" and "to" to "tospace" to avoid a clash with the Python reserved word from. #2084
• ImageInput API changes for thread safety and statelessness #1927 (1.9.2)
  • seek_subimage() no longer takes an ImageSpec&, to avoid the obligatory copy. (If the copy is desired, just call spec() to get it afterwards.)
  • All of the read_*() methods now have varieties that take arguments specifying the subimage and mip level. The read_native_*() methods supplied by ImageInput subclass implementations now ONLY come in the variety that takes a subimage and miplevel.
  • All of the read_*() calls that take subimage/miplevel explicitly are guaranteed to be stateless and thread-safe against each other (it's not necessary to call seek_subimage first, nor to have to lock a mutex to ensure that another thread doesn't change the subimage before you get a chance to call read). For back-compatibility, there are still versions that don't take subimage/miplevel, require a prior call to seek_subimge, and are thus not considered thread-safe.
  • New methods spec(subimage,miplevel) and spec_dimensions(s,m) let you retrieve a copy of the ImageSpec for a given subimage and MIP level (thread-safe, and without needing a prior seek_subimage) call. Note that to be stateless and thread-safe, these return a COPY of the spec, rather than the reference returned by the stateful spec() call that has no arguments and requires a prior seek_subimage. However, spec_dimensions() does not copy the channel names or the arbitrary metadata, and is thus very inexpensive if the only thing you need from the spec copy is the image dimensions and channel formats.
• ImageInput and ImageOutput create/open changes
  • The static create() and open() methods have been changed so that instead of returning an ImageInput * (or ImageOutput *) and requiring the caller to correctly manage that resource and eventually destroy it, now they return a unique_ptr that automatically deletes when it leaves scope. In the process we also clean up some edge cases on Windows where it was possible for ImageInput/ImageOutput to have been allocated in one DLL's heap but freed in a different DLL's heap, which could cause subtle heap corruption problems. #1934,#1945 (1.9.3).
• ImageBuf
  • New method set_origin() changes the pixel data window origin. #1949 (1.9.4)
  • Assignment (operator=) is now enabled for ImageBuf, both the copying and moving variety. Also, an explicit copy() method has been added that returns a full copy of the ImageBuf. #1952 (1.9.4)
  • write() method has had its arguments changed and now takes an optional TypeDesc that lets you specify a requested data type when writing the output file, rather than requiring a previous and separate call to set_write_format(). The old call signature of write() still exists, but it will be considered deprecated in the future. #1953 (1.9.4)
• ImageBufAlgo
  • In C++, functions that take raw pointers for per-channel constant values or results are deprecated, in favor of new versions that heavily rely on span<> to safely pass array references and their lengths. #1961 (1.9.4)
  • In both C++ and Python, every IBA function that takes a parameter giving an ImageBuf destination reference for results have an additional variant that directly returns an ImageBuf result. This makes much cleaner, more readable code, in cases where it's not necessary to write partial results into an existing IB. #1961 (1.9.4)
  • In C++, many IBA functions that came in multiple versions for whether certain parameters could be an image, a per-channel constant, or a single constant, have been replaced by a single version that takes a new parameter-passing helper class, Image_or_Const that will match against any of those choices. (No changes are necessary for calling programs, but it makes the header and documentation a lot simpler.) #1961 (1.9.4)
  • IBA compare(), computePixelStats(), and histogram() now directly return their result structures, intead of requiring the passing of a destination reference. #1961 (1.9.4)
  • New IBA::fit() resizes and image to just fit in the given size, but preserve its aspect ratio (padding with black as necessary). It's just like what oiiotool --fit has always done, but now you can call it directly from C++ or Python. #1993 (1.9.4)
  • New contrast_remap() allows flexible linear or sigmoidal contrast remapping. #2043 (1.9.4)
  • ImageBufAlgo::colorconvert and various ocio transformations have changed the default value of their unpremult parameter from false to true, reflecting the fact that we believe this is almost always the more correct choice. Also, if their input image is clearly marked as having unasociated alpha already, they will not bracket the color conversion with the requested unpremult/premult. #1864 (1.9.2)
  • Updated the OpenCV interoperability with new functions to_OpenCV (make an ImageBuf out of a cv::Mat) and from_OpenCV (fill in a cv::Mat with the contents of an ImageBuf). Deprecated the old from_IplImage and to_IplImage, which are very OpenCV-1.x-centric. (2.0.2)
• ImageCache/TextureSystem:
  • ImageCache and TextureSystem now have close(filename) and close_all() methods, which for one file or all files will close the files and release any open file handles (also unlocking write access to those files on Windows), but without invalidating anything it knows about the ImageSpec or any pixel tiles already read from the files, as would happen with a call to the much more drastic invalidate() or invalidate_all(). #1950 (1.9.4)
  • TextureSystem::create() has an additional optional argument that allows the caller to pass an existing app-owned custom ImageCache. #2019 (1.9.4)
  • New TextureSystem::imagecache() method returns a blind, non-owning pointer to the underlying ImageCache of that TS. #2019 (1.9.4)
  • ImageCache: extended add_tile() with an optional copy parameter (which defaults to true), which when set to false will make a tile that references an app buffer without allocating, copying, and owning the memory. In short, this makes it possible to reference existing memory holding an image array, as if it were a texture. #2012 (1.9.4)
  • ImageCache::add_file() extended with an optional replace parameter (default: false), that if true, will replace the tile and invalidate the old one. #2021 (1.9.4)
• Changes to string formatting: #2076 (2.0.1)
  • New Strutil::sprintf() and ustring::sprintf() functions are for printf-style formatted errors and warnings. You are encouraged to change your existing format() calls to sprintf(), since the original format may in a later version (2.1?) switch to Python-style formatting commands, but sprintf will continue to reliably use C printf style notation.
  • In ImageInput, ImageOutput, ImageBuf, and ErrorHandler, new errorf() and warningf() methods similarly provide printf-style formatted errors and warnings. The old error()/warning() calls will someday (maybe 2.1?) switch to Python-style formatting commands, but errorf will continue to reliably use C printf style notation.
• ColorConfig changes: ColorConfig methods now return shared pointers to ColorProcessor rather than raw pointers. It is therefore no longer required to make an explicit delete call. Created ColorProcessor objects are now internally cached, so asking for the same color transformation multiple times is no longer expensive. The ColorProcessor interface is now in color.h and can be directly used to perform transformations on individual colors (previously it was just an opaque pointer and could only be used to pass into certain IBA functions). The color space names "rgb" and "default" are now understood to be synonyms for the default "linear" color space. #1788 (1.9.0)
• Remove long-deprecated API calls:
  • ImageBuf::get_pixels/get_pixel_channels varieties deprecated since 1.6.
  • ImageBuf::set_deep_value_uint, deprecated since 1.7.
  • ImageBuf::deep_alloc, deprecated since 1.7.
  • ImageBufAlgo::colorconvert variety deprecated since 1.7.
  • ImageCache::clear, deprecated since 1.7.
  • ImageCache::add_tile variety deprecated since 1.6.
• ROI new methods: contains() #1874, #1878 (1.9.2)
• ImageBufAlgo::pixeladdr() now takes an additional optional parameter, the channel number. #1880 (1.9.2)
• Global OIIO attribute "log_times" (which defaults to 0 but can be overridden by setting the OPENIMAGEIO_LOG_TIMES environment variable), when nonzero, instruments ImageBufAlgo functions to record the number of times they are called and how much time they take to execute. A report of these times can be retrieved as a string as the "timing_report" attribute, or it will be printed to stdout automatically if the value of log_times is 2 or more at the time that the application exits. #1885 (1.9.2)
• Moved the definition of ROI from imagebuf.h to imageio.h and make most of the methods constexpr. #1906 (1.9.2)
• Rename/move of array_view to span. Deprecated array_view and moved array_view.h contents to span.h. You should change array_view<T> to span<T> and array_view<const T> to cspan<T>. #1956,2062 (1.9.4)
• ustring: removed operator int() that allowed simple int casting such as:

      ustring u, v;
      if (u || !v) { ... }
  

  This was error-prone, neither std::string nor std::string_view had the equivalent, so we are removing it. The preferred idiom is:

      if (!u.empty() || v.empty()) { ... }
  

Performance improvements:

• ImageBufAlgo::computePixelStats is now multithreaded and should improve by a large factor when running on a machine with many cores. This is particularly noticable for maketx. #1852 (1.9.2)
• Color conversions are sped up by 50% for 4 channel float images, about 30% for other combinations of channels or data formats. #1868 (1.9.2)
• ImageBuf::get_pixels() sped up by around 3x for the common case of the image being fully in memory (the slower path is now only used for ImageCache-based images). #1872 (1.9.2)
• ImageBufAlgo::copy() and crop() sped up for in-memory buffers, by about 35-45% when copying between buffers of the same type, 2-4x when copying between buffers of different data types. #1877 (1.9.2)
• ImageBufAlgo::over() when both buffers are in-memory, float, 4-channels, sped up by about 2x. #1879 (1.9.2).
• ImageBufAlgo::fill() of a constant color sped up by 1.5-2.5x (depending on the data type involved). #1886 (1.9.2)

Fixes and feature enhancements:

• oiiotool
  • --help prints important usage tips that explain command parsing, syntax of optional modifiers, and the path to PDF docs. #1811 (1.9.2)
  • --colormap has new maps "inferno", "magma", "plasma", "viridis", which are perceptually uniform, monotonically increasing luminance, look good converted to greyscale, and usable by people with color blindness. #1820 (1.9.2)
  • oiiotool no longer enables autotile by default. #1856 (1.9.2)
  • --colorconvert, --tocolorspace, and all of the --ocio commands now take an optional modifier :unpremult=1 which causes the color conversion to be internally bracketed by unpremult/premult steps (if the image has alpha and is not already marked as having unassociated alpha). You should therefore prefer --colorconvert:unpremult=1 from to rather than the more complex --unpremult --colorconvert from to -premult. #1864 (1.9.2)
  • --autocc will also cause unpremult/premult to bracket any color transformations it does automatically for read and write (if the image has alpha and does not appear to already be unassociated). #1864 (1.9.2)
  • --help prints the name of the OCIO color config file. #1869 (1.9.2)
  • Frame sequence wildcard improvements: fix handling of negative frame numbers and ranges, also the --frames command line option is not enough to trigger a loop over those frame numbers, even if no other arguments appear to have wildcard structure. #1894 (1.8.10/1.9.2)
  • --info -v now prints metadata in sorted order, making it easier to spot the existence of particular metadata. #1982 (1.9.4)
  • --no-autopremult fixed, it wasn't working properly for cases that were read directly rather than backed by ImageCache. #1984 (1.9.4)
  • New --contrast allows for contrast remapping (linear or sigmoidal). #2043 (1.9.4)
  • Improved logic for propagating the pixel data format through multiple operations, especially for files with multiple subimages. #1769 (1.9.0/1.8.6)
  • Outputs are now written to temporary files, then atomically moved to the specified filename at the end. This makes it safe for oiiotool to "overwrite" a file (i.e. oiiotool in.tif ... -o out.tif) without problematic situations where the file is truncated or overwritten before the reading is complete. #1797 (1.8.7/1.9.1)
  • Fixed problem with reading half files where very small (denormalized) half values could get squashed to float 0.0 instead of having their values preserved, if certain old versions of libopenjpeg were being used (because they set a CPU flag strangely upon library load and then never changed it back, this is a libopenjpeg bug that has since been fixed). #2048 (2.0)
  • -d chan=type logic fixed for certain cases of specifying the data types of individual channels. #2061 (2.0beta2)
  • Expression evaluation: metadata names can now be enclosed in single or double quotes if they don't follow "C" identifier naming conventions. For example, {TOP.'foo/bar'} retrieves metadata called "foo/bar" rather than trying to retrieve "foo" and divide by bar. #2068 (2.0beta2)
  • Expression evaluation: When retrieving metadata, timecode data will be expressed properly as a string ("00:00:00:00"). #2068 (2.0beta2)
• ImageBufAlgo:
  • color_map() supports new maps "inferno", "magma", "plasma", "viridis". #1820 (1.9.2)
  • Across many functions, improve channel logic when combining an image with alpha with another image without alpha. #1827 (1.9.2)
  • mad() now takes an img*color+img variety. (Previously it supported img*img+img and img*color+color.) #1866 (1.9.2)
  • New fit() is like resize but fits inside a specified window size, while preserving the aspect ratio of the image appearance. #1993.
  • New contrast_remap() allows flexible linear or sigmoidal contrast remapping. #2043 (1.9.4)
  • channel_append() is no longer limited to requiring the two input images to have the same pixel data type. #2022 (1.9.4)
  • isConstantColor(), isConstantChannel(), and isMonochrome() have added an optional threshold parameter that allows you to compute whether the image is constant or monochrome within a non-zero tolerance (the default is still 0.0, meaning checking for an exact match). #2049 (2.0.0)
  • IBA::ociodisplay() has better behavior when its "fromspace" parameter is left blank -- instead of assuming "linear" (as a space name), it assumes it's whatever space in your OCIO color config has the "linear" role. #2083 (1.8.17/2.0.1)
• ImageBuf:
  • Bug fixed in IB::copy() of rare types. #1829 (1.9.2)
  • write() automatically tells the ImageCache to 'invalidate' the file being written, so cached images will not retain the prior version of the files. #1916 (1.9.2)
  • Bug fix to ImageBuf::contains_roi() method -- it erroneously always returned true. #1997 (1.8.14/1.9.4)
• ImageCache/TextureSystem/maketx:
  • Improved stats on how long we wait for ImageInput mutexes. #1779 (1.9.0/1.8.6)
  • Improved performance of IC/TS tile and file caches under heavy contention from many threads. #1780 (1.9.0)
  • Increased the default max_tile_channels limit from 5 to 6. #1803 (1.9.1)
  • maketx: improved image hashing to avoid some (extremely rare) possible hash collisions. #1819 (1.9.2)
  • IC/TS performance improvements by changing the underlying hash table implementation. #1823,1824,1825,1826,1830 (1.9.2)
  • texture()/texture3d(): when requesting a nonexistent "subimage", return the fill color, like we do when requesting nonexistent channels (rather than nondeterministically simply not filling in the result). #1917 (1.9.2)
  • Relying on some changes to the ImageInput API, there is now much less thread locking to protect the underlying ImageInputs, and this should improve texture and image cache performance when many threads need to read tiles from the same file. #1927 (1.9.2)
  • get_image_info()/get_texture_info() is now more flexible about retrieving arrays vs aggregates, in cases where the total number of elements is correct. #1968 (1.9.4)
  • Fix uninitialized read within the texture system (only affected statistics, never gave wrong texture results). #2000 (1.9.4)
  • texture3d() transforms lookup points from world into local space if the file has a "worldtolocal" metadata giving a 4x4 matrix. #2009 (1.9.4)
  • Fix minor texture filtering bug where widely disparate "sblur" and "tblur" values could in some circumstances lead to incorrect texture filter estimation. #2052 (2.0.0)
  • ImageCache::invalidate(filename) did not properly invalidate the "fingerprint" is used to detect duplicate files. #2081 (1.8.17/2.0.1)
• iv:
  • Fix (especially on OSX) for various ways it has been broken since the shift to Qt5. #1946 (1.8.12, 1.9.4)
  • New optin --no-autopremult works like oiiotool, causes images with unassociated alpha to not be automatically premultiplied by alpha as they are read in. #1984 (1.9.4)
• All string->numeric parsing and numeric->string formatting is now locale-independent and always uses '.' as decimal marker. #1796 (1.9.0)
• Python Imagebuf.get_pixels and set_pixels bugs fixed, in the varieties that take an ROI to describe the region. #1802 (1.9.2)
• Python: Implement missing ImageOutput.open() call variety for declaring multiple subimages. #2074 (2.0.1)
• More robust parsing of XMP metadata for unknown metadata names. #1816 (1.9.2/1.8.7)
• Fix ImageSpec constructor from an ROI, display/"full" window did not get the right default origin. #1997 (1.8.14/1.9.4)
• ImageSpec::erase_attribute() fix bug where it got case-sensitivity of the search backwards when built using std::regex rather than boost::regex. #2003 (1.8.14/1.9.4)
• DPX:
  • Better catching of write errors, including filling the disk while in the process of writing a DPX file. #2072 (2.0.1)
• Field3d:
  • Prevent crashes when open fails. #1848 (1.9.2/1.8.8)
  • Fix potential mutex deadlock. #1972 (1.9.4)
• GIF:
  • Fix crash when reading GIF with comment extension but no comment data. #2001 (1.8.14/1.9.4)
• JPEG:
  • When writing, be robust to accidentally setting the "density" metadata to values larger than JPEG's 16 bit integer field will accommodate. #2002 (1.8.14/1.9.4)
  • Better detection and reporting of error conditions while reading corrupt JPEG files. #2073 (2.0.1)
• OpenEXR:
  • Gracefully detect and reject files with subsampled channels, which is a rarely-to-never-used OpenEXR feature that we don't support properly. #1849 (1.9.2/1.8.8)
  • Improved handling of UTF-8 filenames on Windows. #1941 (1.9.3, 1.8.12, 1.7.19)
• PNG:
  • Fix redundant png_write_end call. #1910 (1.9.2)
• PSD:
  • Fix parse issue of layer mask data. #1777 (1.9.2)
• RAW:
  • Add "raw:HighlightMode" configuration hint to control libraw's handling of highlight mode processing. #1851
  • Important bug fix when dealing with rotated (and vertical) images, which were not being re-oriented properly and could get strangely scrambled. #1854 (1.9.2/1.8.9)
  • Major rewrite of the way makernotes and camera-specific metadata are handled, resulting in much more (and more accurate) reporting of camera metadata. #1985 (1.9.4)
  • The "oiio:ColorSpace" metadata is now set correctly when reading raw DSLR images. And we deprecate the old "raw:ColorSpace" metadata, which is useless. #2016 (1.9.4)
  • Add "raw:aber" configuration hint to control libraw's adjustments for chromatic aberration. This data is of type "float[2]", the first value is the scale factor for red, the second for blue, and both should be very close to 1.0. #2030 (1.9.4)
• TIFF:
  • Improve performance of TIFF scanline output. #1833 (1.9.2)
  • Bug fix: read_tile() and read_tiles() input of un-premultiplied tiles botched the "shape" of the tile data array. #1907 (1.9.2/1.8.10)
  • Improvement in speed of reading headers (by removing redundant call to TIFFSetDirectory). #1922 (1.9.2)
  • When config option "oiio:UnassociatedAlpha" is nonzero (or not set -- which is the default), therefore enabling automatic premultiplication by alpha for any unassociated alpha files, it will set the metadata "tiff:UnassociatedAlpha" to indicate that the original file was unassociated. #1984 (1.9.4)
  • Bug fixes for TIFF reads of images with unassociated alpha -- there were some edge cases where they pixels failed to automatically premultiply upon read. #2032 (1.9.4)
• zfile: more careful gzopen on Windows that could crash when given bogus filename. #1839,2070 (1.9.2/1.8.8/2.0.1)
• Windows fix: Safer thread pool destruction on. #2038 (1.9.4)

Build/test system improvements and platform ports:

• Fixes for Windows build. #1793, #1794 (1.9.0/1.8.6), #2025 (1.9.4)
• Fix build bug where if the makefile wrapper got CODECOV=0, it would force a "Debug" build (required for code coverage tests) even though code coverage is instructed to be off. (It would be fine if you didn't specify CODECOV at all.) #1792 (1.9.0/1.8.6)
• Build: Fix broken build when Freetype was not found or disabled. #1800 (1.8.6/1.9.1)
• Build: Boost.Python is no longer a dependency, but pybind11 is. If not found on the system, it will be automatically downloaded. #1801, #2031 (1.9.1)
• Time for a multi-core build of OIIO is reduced by 40% by refactoring some extra big modules into more bite-sized pieces. #1806 (1.9.2)
• testtex:
  • Make the "thread workout" cases all honor --handle. #1778 (1.9.0)
  • Only prints detailed stats if -v is used, and new option --invalidate will invalidate the cache when starting each threadtimes trial. #1828 (1.9.2)
  • New --anisoratio lets you choose anisotropic shape for thread working tests, and make thread_workout samples twice as big to be more typical by interpolating mip levels. #1840 (1.9.2)
  • TextureSystem stats are printed as well as ImageCache. #1840 (1.9.2)
• iv no longer requires GLEW, using QOpenGLFunctions instead. #1840 (1.9.2)
• DICOM: Fix dcmtk build errors on some platforms. Also, the minimum dcmtk version we support is 3.6.1. #1843 (1.9.2/1.8.8)
• Build fixes for Hurd OS. #1850 (1.9.2/1.8.8)
• Clean up leak sanitizer errors. #1855 (1.9.2)
• On Unix/Linux, add explicit DL library dependency to libOpenImageIO.so itself instead of only to the binaries and test utilities. #1860 (1.9.2/1.8.8)
• The build now bundles a sample OCIO config in testsuite/common so that we can do OCIO-based unit tests. #1870 (1.9.2)
• Properly find newer openjpeg 2.3. #1871 (1.9.2)
• Fix testsuite to be Python 2/3 agnostic. #1891 (1.9.2)
• Removed USE_PYTHON3 build flag, which didn't do anything. #1891 (1.9.2)
• The PYTHON_VERSION build variable is now better at selecting among several installed versions of Python, and all the tests should work fine with Python 3.x now. #2015 (1.9.4)
• Remove some lingering support for MSVS < 2013 (which we haven't advertised as working anyway). #1887 (1.9.2)
• Windows/MSVC build fix: use the /bigobj option on some large modules that need it. #1900, #1902 (1.8.10/1.9.2)
• Add up-to-date Nuke versions to FindNuke.cmake. #1920 (1.8.11, 1.9.2)
• Allow building against ffmpeg 4.0. #1926,#1936 (1.8.11, 1.9.2)
• Disable SSE for 32 bit Windows -- problematic build issues. #1933 (1.9.3, 1.8.12, 1.7.19)
• Fixes to the EMBEDPLUGINS=0 build case, which had at some point stopped working properly. #1942 (1.9.3)
• Improvements in finding the location of OpenJPEG with Macports. #1948 (1.8.12, 1.9.4)
• Improvement finding libraw properly on Windows. #1959 (1.9.4)
• Fix warnings to allow clean gcc8 builds. #1974 (1.9.4)
• Make sure we build properly for C++17. (1.9.4)
• Check properly for minimal FFMpeg version (2.6). #1981 (1.9.4)
• New build option GLIBCXX_USE_CXX11_ABI, when set to 0 will force the old gcc string ABI (even gcc 7+ where the new ABI is the default), and if set to 1 will force the new gcc string ABI (on gcc 5-6, where old ABI is the default). If not set at all, it will respect the default choice for that compiler. #1980 (1.9.4)
• TravisCI builds now use an abbreviated test matrix for most ordinary pushes of working branches, but the full test matrix for PRs or pushes to "master" or "RB" branches. #1983 (1.9.4)
• Support compilation by clang 7.0. #1995 (1.9.4)
• Support for building against OpenEXR 2.3. #2007 (1.9.4)
• Use OpenEXR pkgconfig if available. #2008 (1.9.4)
• Allow builds outside the source tree to pass testsuite. Defaults to finding test image directories such as oiio-images, openexr-images, and libtiffpic in the usual ".." from the main OIIO source directory, but now it can be overridden with the CMake variable OIIO_TESTSUITE_IMAGEDIR. #2026 (1.9.4)
• Remove stale python examples from src/python. They were untested, undocumented, and probably no longer worked against the current APIs. #2036 (1.9.4)
• Fixes for Windows when making Unicode builds, and fix Plugin::dlopen on Windows to properly support UTF-8 filenames. #1454 (2.0.1)
• Support added for OpenCV 4.0. (2.0.1)

Developer goodies / internals:

• Formatting with clang-format: All submissions are expected to be formatted using our standard clang-format rules. Please run make clang-format prior to submitting code. The TravisCI tests include one entry just to check that the formatting conforms, and will fail if it doesn't, printing the diffs that would bring it to proper formatting. (Note: for small changes, if you don't have clang-format locally, it's ok to submit, then use the diffs from the failures to fix it by hand and resubmit and update.) #2059,2064,2065,2067,2069.
• argparse.h:
  • Add pre- and post-option help printing callbacks. #1811 (1.9.2)
  • Changed to PIMPL to hide implementation from the public headers. Also modernized internals, no raw new/delete. #1858 (1.9.2)
• array_view.h:
  • Added begin(), end(), cbegin(), cend() methods, and new constructors from pointer pairs and from std::array. (1.9.0/1.8.6)
  • Deprecated, moved contents to span.h. You should change array_view<T> to span<T> and array_view<const T> to cspan<T>. #1956 (1.9.4)
• color.h: add guards to make this header safe for Cuda compilation. #1905 (1.9.2/1.8.10)
• filesystem.h:
  • IOProxy classes that can abstract file operations for custom I/O substitutions. #1931 (1.9.3)
  • Proper UTF-8 filenames for unique_path() and temp_directory(), and general UTF-8 cleanup/simplification. #1940 (1.9.3, 1.8.12, 1.7.19)
  • Remove extraneous calls to exists() that were doubling the number of stat syscalls. #2385 (2.1.8)
• fmath.h:
  • Now defines preprocessor symbol OIIO_FMATH_H so other files can easily detect if it has been included. (1.9.0/1.8.6)
  • Modify to allow Cuda compilation/use of this header. #1888,#1896 (1.9.2/1.8.10)
  • Improve numeric approximation of fast_atan() and fast_atan2(). #1943 (1.9.3)
  • fast_cbrt() is a fast approximate cube root (maximum error 8e-14, about 3 times faster than pow computes cube roots). #1955 (1.9.4)
• function_view.h: Overhauled fixed with an alternate implementation borrowed from LLVM. (1.9.4)
• hash.h: add guards to make this header safe for Cuda compilation. #1905 (1.9.2/1.8.10)
• imageio.h: convert_image() and parallel_convert_image have been simplified to remove optional alpha_channel and z_channel parameters that were never actually used. The old versions are still present but are deprecated. #2088 (2.0.1)
• parallel.h:
  • parallel_options passed to many functions. #1807 (1.9.2)
  • More careful avoidance of threads not recursively using the thread pool (which could lead to deadlocks). #1807 (1.9.2)
  • Internals refactor of task_set #1883 (1.9.2).
  • Make the thread pool better behaved in times if pool congestion -- if there are already way too many items in the task queue, the caller may do the work itself rather than add to the end and have to wait too long to get results. #1884 (1.9.2)
• paramlist.h:
  • ParamValue class has added get_int_indexed() and get_float_indexed() methods. #1773 (1.9.0/1.8.6)
  • ParamValue restructured to allow additional common data types to store internally rather than requre an allocation. #1812 (1.9.2)
  • New ParamList convenience methods: remove(), constains(), add_or_replace(). #1813 (1.9.2)
• platform.h:
  • New OIIO_FALLTHROUGH and OIIO_NODISCARD macros, and renamed OIIO_UNUSED_OK to OIIO_MAYBE_UNUSED (to match C++17 naming). #2041
• simd.h:
  • Fixed build break when AVX512VL is enabled. #1781 (1.9.0/1.8.6)
  • Minor fixes especially for avx512. #1846 (1.9.2/1.8.8) #1873,#1893 (1.9.2)
• span.h:
  • Used to be array_view. Now it's span<> and span_strided. Also, cspan<T> is a handy alias for span<const T>. #1956 (1.9.4)
  • Added begin(), end(), cbegin(), cend() methods, and new constructors from pointer pairs and from std::array. (1.9.0/1.8.6)
  • Added == and != to span and span_strided. #2037 (1.9.4)
• strutil.h:
  • All string->numeric parsing and numeric->string formatting is now locale-independent and always uses '.' as decimal marker. #1796 (1.9.0)
  • New Strutil::stof(), stoi(), stoui(), stod() functions for easy parsing of strings to numbers. Also tests Strutil::string_is_int() and string_is_float(). #1796 (1.9.0)
  • New to_string<> utility template. #1814 (1.9.2)
  • Fix to strtof, strtod for non-C locales. #1918 (1.8.11, 1.9.2)
  • New iless() is case-insensitive locale-independent string_view ordering comparison. Also added StringIEqual, StringLess, StringILess functors. (1.9.4)
  • join() is now a template that can act on any iterable container of objects that allow stream output. #2033 (1.9.4)
  • New splits()/splitsv() that direction returns a vector of std::string or string_view, respectively. #2033 (1.9.4)
  • A second version of extract_from_list_string that directly returns a std::vector (instead of being passed as a param). #2033 (1.9.4)
  • parse_string now accepts single quotes as well as double quotes to enclose a quoted string. #2066 (2.0beta2)
  • Fix Strutil::vsnprintf detection of encoding errors on Windows. #2082 (1.8.17/2.0.1)
  • parse_string() - fix bugs that would fail for escaped quotes within the string. #2386 (2.1.8)
• thread.h:
  • Reimplementation of spin_rw_mutex has much better performance when many threads are accessing at once, especially if most of them are reader threads. #1787 (1.9.0)
  • task_set: add wait_for_task() method that waits for just one task in the set to finish (versus wait() that waits for all). #1847 (1.9.2)
  • Fix rare crash in thread pool when lowering the number of threads. #2013 (1.9.4/1.8.15)
• unittest.h:
  • Made references to Strutil fully qualified in OIIO namespace, so that unittest.h can be more easily used outside of the OIIO codebase. #1791 (1.9.0)
  • OIIO_CHECK_EQUAL_APPROX - fix namespace ambiguity. #1998 (1.9.4)
  • OIIO_CHECK_EQUAL now can compare two std::vectors. #2033 (1.9.4)
  • Make unit test errors respect whether stdout is a terminal when deciding whether to print in color. #2045
• Extensive use of C++11 final and override decorators of virtual methods in our internals, especially ImageInput and ImageOutput. #1904 (1.9.2)

Notable documentation changes:

• A new THIRD-PARTY.md file reproduces the full open source licenses of all code that we distribute with OIIO, incorporate, or derive code from. They are have very similar license terms to the main OIIO license ("New BSD") -- MIT, Mozilla, Apache 2.0, or public domain. OIIO does not use any GPL or other "viral" licenesed code that would change license terms of any code that didn't come directly from those packages.
• The CHANGES.md file was getting truly enormous, so we have split the release notes from the 0.x and 1.x releases into separate files found in src/doc. So CHANGES.md only documents 2.0 and beyond.

---

For older release notes, see:

• CHANGES-0.x.
• CHANGES-1.x.