pbmtogem
converts PBM bitmaps to GEM IMG format
TLDR
Convert PBM to GEM IMG format
$ pbmtogem [input.pbm] > [output.img]
SYNOPSIS
pbmtogem [file]
DESCRIPTION
pbmtogem converts PBM bitmaps to GEM IMG format. GEM (Graphics Environment Manager) was a GUI system used on Atari ST and early PCs. Part of Netpbm toolkit.