pnmtosgi

Convert a PNM file to an SGI image file. More information: https://netpbm.sourceforge.net/doc/pnmtosgi.html.

pnmtosgi path/to/input.pnm > path/to/output.sgi

pnmtosgi -verbatim|rle path/to/input.pnm > path/to/output.sgi

pnmtosgi -imagename string path/to/input.pnm > path/to/output.sgi