pnmcrop

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

• Remove white borders on a PNM image:

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

• Remove borders of the specified color that are on the top and left side of the image:

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

• Determine the color of the borders to be removed by the color of the pixel in the specified corner:

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

• Leave a border with a width of n pixels. Additionally, specify the behaviour if the image is entirely made out of background:

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