rasttopnm
Convert a Sun rasterfile to a PNM file.
TLDR
Convert a RAST image to a PNM file
$ rasttopnm [path/to/input.rast] > [path/to/output.pnm]
Use the color map indices in the raster if they are color values
$ rasttopnm -index [path/to/input.rast] > [path/to/output.pnm]
