ASPNetImage

A COM Interop wrapper written in C# for the .NET 2.0 System.Drawing namespace meant as a drop-in replacement for the third-party ASPImage component by ServerObjects Inc.

While attemting to perform a web server update to Windows Server 2008 for a classic ASP app, I discovered that the long-used ASPImage 2.x COM object no longer functions, exiting with a memory error. Research into the issue for a solution unearthed a handful of reports from people experiencing the same issue and no luck with customer support or locating an inexpensive, drop-in alternative. Thus this replacement was born :)

The ASPNetImage component essentially exposes part of the System.Drawing namespace to classic ASP via an interop COM object using the interface outlined by ServerObjects' ASPImage 2.x component. Switching from ASPImage to ASPNetImage requires you to only register the new DLL and change the object reference in Server.CreateObject() calls in your code. No other changes are required.

A debug and release build of the DLL is included in the repository, or you can compile it yourself after generating a signing key. Checkout a working copy of the source repository or you may download the current release in the Downloads section.

Environment Configuration

• Visual Studio 2010 or greater

• Install and configure NUnit. TestDriven.NET, which provides NUnit is available at http://testdriven.net/ You will need to add a reference to "nunit.framework.dll" in the UnitTests project.

• Configure DLL signing. In Visual Studio, open the ASPNetImage project properties and click on the "Signing" tab. Check the box labeled "Sign the assembly" and select "< New >" from the "Choose a strong name key file:" dropdown and follow the prompts.

• You should be able to build the DLL and run the unit tests at this point.

Troubleshooting

Installation Issues

• Verify that the .NET Framework v2.0 is installed and working properly.

• Ensure that you've registered the DLL with REGASM.EXE with the /tlb and /codebase command line switches (see the included register.bat file). You may want to unregister the DLL and re-register them to confirm.

• Make sure the DLL and TLB files have the correct file permissions. Give read/write/execute access to NETWORK, NETWORK_SERVICE and the IUSER_[machineName] accounts.

• If you are using an unsigned DLL, you will receive the following error message when registering the DLL with REGASM.EXE:

  RegAsm : warning RA0000 : Registering an unsigned assembly with /codebase can cause your assembly to interfere with other applications that may be installed on the same computer. The /codebase switch is intended to be used only with signed assemblies. Please give your assembly a strong name and re-register it.""

  The object should still work, but I'd recommend unregistering it, compiling and signing the DLL yourself before registering it again so that you don't receive the warning message. Visual Studio 2005 and up can do this automatically from the Project Properties panel on the "Signing" tab. Just pick "< New >" and follow the prompts.

Other

• As of this writing, the precompiled DLL is only provided in 32bit format. There may be unknown issues running this on a 64bit OS. Precompiled 64bit variations are planned for sometime in the future.

• Some image format variations have been known to cause issues. Try alternate images from a different source. If you experience issues loading certain images and not others, please provide the problem image(s) if possible along with a bug report.

Properties and Methods

ASPNetImage is a work in progress and any help completing the object is appreciated. All properties and methods are stubbed out, but as of this writing, currently only a small subset of properties and methods are implemented either in part or whole.

Properties

• AntiAliasText:boolean
  Gets or sets whether anti-aliased text is added on the image. Default is true.

• AutoClear:boolean
  If true, class will automatically dispose image data when the SaveImage method is called. Default is true.

• BackgroundColor:int
  Gets or sets the background color for future image manipulations.

• Bold:boolean
  Gets or sets whether text is to be rendered in bold faced style. Default is false.

• ConstrainResize:boolean
  When set to true, automatically crops the image during a resize to fit the dimensions and retain the original image's aspect ratio. Default is true. New with ASPNetImage.

• DPI:int
  Gets or sets the DPI for the current image. Default is 96.

• Error:string
  Partially implemented. Returns the last error from LoadImage and SaveImage methods only.

• Expires:DateTime
  Returns the date that the component expires. Included for compatibility. Always returns future date.

• Filename:string
  Gets or sets the full path and filename to be used by the SaveImage method.

• FontColor:int
  Gets or sets the argb color value to be used when rendering text.

• FontName:string
  Gets or sets the name of the font to be used when drawing text. Default is "MS Sans Serif."

• FontSize:int
  Gets or sets the pixel size of the font to be used when rendering text. Default is 12 pixels.

• ImageFormat:int
  Partially implemented. Gets or sets the image format to be used by the SaveImage method. Currently only JPEG format is supported for output. Enumerated. See ASPNetImage.ImageFormats.

• JPEGQuality:int
  Gets or sets the output quality percentage of JPEG images when SaveImage is called to save a JPEG. Valid amounts are 1 to 100.

• MaxX:int
  Gets or sets the width of the image.

• MaxY:int
  Gets or sets the height of the image.

• PenColor:int
  Gets or sets the argb color value to be used when drawing using the pen.

• PenStyle:int
  Gets or sets the line style to be used when drawing using the pen.

• PenWidth:int
  Gets or sets the pixel width of the pen when drawing.

• ProgressiveJPEGEncoding:boolean
  Gets or sets whether JPG images should be saved with progressive encoding.

• RawNetImage:Image
  Returns the .NET Image instance.

• RegisteredTo:string
  Gets or sets the name that the component is registered to. Included for compatibility. Returns "This Organization" by default, but can be set to any string.

• TextAngle:int
  Gets or sets the angle to be used when rendering text. Default is 0 (horizontal).

• Version:string
  Returns last known ASPImage version with "(ASPNetImage vX.X)" appended.

• X:Int32
  Gets or sets the current X coordinate of the pen used for drawing.

• Y:Int32
  Gets or sets the current X coordinate of the pen used for drawing.

Methods

• AddImage
  Adds a new image to the canvas using the provided coordinates.

• BrightenImage
  Increases the brightness of the image.

• ClearImage
  Clears the image.

• Contrast
  Modifies the image's contrast.

• CreateGrayScale
  Converts the image into a gray scale image.

• CreateNegative
  Creates a negative image effect of the current image.

• CropImage
  Crops the image.

• DarkenImage
  Darkens the image.

• Emboss
  Creates an embossing effect on the image.

• FillRect
  Fills a rectangle area of the image with a given color.

• FlipImage
  Flips the image.

• GetImageFileSize
  Returns the image dimensions for the image specified by full file path and name. Currently incurs memory hit as image has to be loaded to determine dimensions.

• GetImageSize
  Returns the image dimensions for the currently loaded image. New with ASPNetImage.

• GetPixel
  Returns the color value (argb) for the pixel at the specified x and y coordinates.

• LineTo
  Draws a line from the current pen coordinates to the specified destination with the current pen color and width.

• LoadBlob
  Loads binary imag data onto the image canvas.

• LoadImage
  Loads an image from disk at the specified filepath.

• Rectangle
  Draws a rectangle with the coordinates of the upper-left and lower-right coordinates provided.

• Resize
  Resizes the image.

• ResizeOnHeight
  Resize proportionally based on height. New with ASPNetImage.

• ResizeOnWidth
  Resize proportionally based on width. New with ASPNetImage.

• ResizeR
  Partially implemented. Calls the Resize method.

• RotateImage
  Partially implemented. Rotates the image. Currently only rotates at 90, 180 and 270 degrees clockwise

• SaveImage
  Partially implemented. Saves the image, but currently only in JPEG format.

• TextHeight
  Returns the text height of a string using the current font, font size and font characteristics.

• TextOut
  Writes a string of text using the current font, font size and font characteristics.

• TextWidth
  Returns the text width for a string value using the current font, font size and font characteristics.