reher@ucunx1.san.uc.edu (Jay R. Reher) (04/17/91)
Can anyone give me any information on on the Sun im8 file format. I seem to get the image data ok, but the color table is really screwed. Any help appreciated.. Thanx in advance ! Jay Reher
srnelson@nelsun.Eng.Sun.COM (Scott R. Nelson) (04/19/91)
From article <1991Apr17.042020.15738@ucunx1.san.uc.edu>, by reher@ucunx1.san.uc.edu (Jay R. Reher): > > Can anyone give me any information on on the Sun im8 file format. > I seem to get the image data ok, but the color table is really screwed. Any > help appreciated.. Thanx in advance ! Since no one else seems to have followed up on this, here's the information that covers color tables for all Sun rasterfile formats: The rasterfile header looks like: struct rasterfile { int ras_magic; /* magic number */ int ras_width; /* width (pixels) of image */ int ras_height; /* height (pixels) of image */ int ras_depth; /* depth (1, 8, or 24 bits) of pixel */ int ras_length; /* length (bytes) of image */ int ras_type; /* type of file */ int ras_maptype; /* type of colormap */ int ras_maplength; /* length (bytes) of following map */ /* color map follows for ras_maplength bytes, followed by image */ }; More information may be found in /usr/include/rasterfile.h. Typically the maplength will be 768 which means there are three sets of color ramps, each 256 bytes long. The first 256 bytes are the red color map, the next green and the last 256 bytes are the blue ramp. If maplength is less than 768, divide by 3 to get the length of each of the red, green and blue ramps. You can read the color ramps directly into a character array and then use the 8-bit index to get the color values from each of the three arrays. --- Scott R. Nelson srnelson@eng.sun.com Sun Microsystems "Proofread carefully to see if you any words out."