Verbose mode (show progress). Enables printout of running scan lines.
Specifies number of colors to use, in bits per pixels, so '-c 8' specifies actually 256 colors (maximum and default).
Only one file in the format of RGBRGB... triplets (Each of R, G, B is a byte) is read from input. This file size is 3 * Width * Height (see '-s' below. If stdin is used for input, this option is implicitly applied. The default (if not '-1') is 3 files with the names RGBFile.R, RGBFile.G, RGBFile.B, each of which is Width * Height bytes.
Specifies the size of the image to read.
Print one line of command line help, similar to Usage above.
If no rgb-file is given, rgb2gif will try to read RGB data from stdin.