notes.txt

height data: kartverket, hoydedata.no

format:
sections are exported as GeoTIFF, and for each tile x there are the following files:

    x.tif               the GeoTIFF heightmap itself. also contains geo metadata.
    x.tif.ovr           overview (3 thumbnails of differing size on separate layers)
    x.tif.aux.xml       geodata and statistics, eg. min and max height, histogram etc.
    x.tfw               tiff world file, alternative to embedded GeoTIFF metadata.
    x.sos               SOSI-format file, geo metadata as well.

the value of a pixel seems to correspond 1:1 to the height in meters.

using either the .tif alone with the embedded GeoTIFF data, the TIFF World File, or the SOSI file
should yield the exact same results.

NOTE: the following is made obsolete by javax.imageio.
(JAI is obsolete. javax.imageio works fine for reading GeoTIFF floating point image data.)

-- BEGIN OBSOLETE INFO --
"I was able to find an alternative Java imaging library called Apache Commons Imaging. 
It is a pure-Java library that consists of a single small JAR file. 
It also supports both reading and writing of the TIFF file format and 
it has built-in support for GeoTIFF tags. It appears to handle all of 
the common compression formats as well."
    -> doesnt seem to support 32bit floating point gamma.

alternative:
https://dzone.com/articles/access-information-geotiff
    -> geotools.org, gt-geotiff
        -> didnt work with my tiff files.... threw DataSourceException

JAI works, but:
maven fails to resolve JAI, _unless_ I add geotools repo and install it.
it seems to pull JAI in as a dependency.
    -> yes indeed, http://download.osgeo.org/webdav/geotools has JAI
-- END OBSOLETE INFO --

// step 0:
// select sub-area of world such that dimensions are divisible by
// data resolution, ie. samples/m^2
// and also divisible by 16 (chunk size)

// step 1:
// area: rectangle2d.float, pixel: point -> global_location: point3d

// step 2:
// global_location: point3d -> local_location: point3d, chunk: point2d

//System.out.println(worldSections.size());