pnmcrop

Crop PNM images. More information: https://netpbm.sourceforge.net/doc/pnmcrop.html.

pnmcrop -white path/to/image.pnm > path/to/output.pnm

pnmcrop -bg-color color -top -left path/to/image.pnm > path/to/output.pnm

pnmcrop -bg-corner topleft|topright|bottomleft|bottomright path/to/image.pnm > path/to/output.pnm

pnmcrop -margins n -blank-image pass|minimize|maxcrop path/to/image.pnm > path/to/output.pnm