pnmtosgi
Convert a PNM file to an SGI image file.
TLDR
Convert a PNM image to an SGI image
$ pnmtosgi [path/to/input.pnm] > [path/to/output.sgi]
Specify whether or not compression should be used
$ pnmtosgi -[verbatim|rle] [path/to/input.pnm] > [path/to/output.sgi]
Write the specified string into the SGI image header's imagename field
$ pnmtosgi -imagename [string] [path/to/input.pnm] > [path/to/output.sgi]
