Reverse Engineering of a Graphics Format?

Jimbo God of Unix asks: "I recently purchased a color laser (Samsung CLP-500) because it claimed to have Linux compatibility. It does, mostly. However, I was irritated to find that the drivers are proprietary (splc, Samsung Printer Language - Color) and somewhat cranky to get working. I was hoping to find some good resources on reverse engineering the graphics format used to drive the printer. I've managed to mostly dissect the file format, so I think I can get the graphics data out, but I don't really know how to proceed to the next step. Are there any good resources for figuring out how to reverse engineer the graphics format? Are there any tools out there that will help me analyze the format (other than hexdump) or tell me if it's close to something else so I don't have to do as much work?" "I have something of an advantage since I can compare the output from the Windows driver to the Linux driver, and I was able to dissect the Windows output file from the info gleaned by dissecting the Linux output file. But I'm kind of stuck at the moment and there don't seem to be too many documents or tools out there for dissecting graphics data.

I thought this might be useful for reverse engineering some of the proprietary image compression formats for web cams as well, but that's a project for another day."