sgitopnm
Convert an SGI file to a PNM file.
TLDR
Convert an SGI image to a PNM file
$ sgitopnm [path/to/input.sgi] > [path/to/output.pnm]
Display information about the SGI file
$ sgitopnm -verbose [path/to/input.sgi] > [path/to/output.pnm]
Extract channel n of the SGI file
$ sgitopnm -channel [n] [path/to/input.sgi] > [path/to/output.pnm]
