Full Name	RAS (Sun Raster Data Format)
Format ID	IG_FORMAT_RAS = 37
File Extension(s)	*.ras
Data Type	Raster Image
Data Encoding	Binary
ImageGear Multipage Support	No
ImageGear Alpha Channel Support	No
ImageGear Platforms Support	WIN32, WIN64, Unix, Unix64, .NET, .NET64, MAC

ImageGear Supported Versions:

N/A

ImageGear Supported Features:

• IG_FLTR_DETECTSUPPORT - autodetection
• IG_FLTR_PAGEREADSUPPORT - single page file reading
• IG_FLTR_PAGEINSERTSUPPORT - single-page file writing

ImageGear Read Support:

• IG_COMPRESSION_NONE:
  • Indexed RGB: 1, 4, 8 bpp;
  • RGB: 24 bpp
• IG_COMPRESSION_RLE:
  • Indexed RGB: 1, 4, 8 bpp;
  • RGB: 24 bpp

ImageGear Write Support:

• IG_COMPRESSION_NONE:
  • Indexed RGB: 1, 8 bpp;
  • RGB: 24 bpp
• IG_COMPRESSION_RLE:
  • Indexed RGB: 1, 8 bpp;
  • RGB: 24 bpp

ImageGear Filter Control Parameters:

Filter Control Parameter	Type	Default Value	Available Values	Description
SAVE_COMPRESSED	INT	0 (FALSE)	TRUE, FALSE	Compression flag. If TRUE the saving image will be RLE compressed.

Comments:

Bitmap images used under the SunOS system and UNIX imaging applications are usually stored in Sun Raster form.

The Sun Raster header contains image data (size and type), and the type and size of the colormap, if present. It also contains a Sun Raster identifying tag called "MagicNumber," which always contains the same value. A type field identifies the version of Sun Raster, the most common are called "Old" and "Standard". These are actually the same format and indicate that the image is not compressed. Other possible versions of Sun Raster files include TIFF and IFF, meaning that the image data was converted from one of these formats.

Following the header is a colormap, if applicable. Most 24 or 32-bit raster images do not use a colormap, but rather store the color values directly with the image data. This is known as "truecolor".

The last element of the Sun Raster file is the image data itself. It is usually in 2D raster format.

References Used:

Brown, C. Wayne, and Barry J. Shepherd. Graphics File Formats: Reference and Guide. Greenwich, CT.: Manning Publications, 1992.

Kay, David C. and John R. Levine. Graphics File Formats. Windcrest Books, 1992.

Murray, James D. and William vanRyper. Encyclopedia of Graphics File Formats. Sebastopol, CA: O'Reilly & Associates, Inc., 1994.