pnmmargin [-white|-black|-color colorspec] size [pnmfile]

This program is part of Netpbm.

pnmmargin adds a border around a PNM image.

You can specify the border color with the -white, -black, and -color
options. If no color is specified, the program makes a guess.

To remove a border of a specified size from an image, use pamcut.
pnmcrop also removes borders, but determines by itself what is border
and what is subject.

For lower level control, including to add different size borders to
different sides of the image, look at pnmcat.

If all you're trying to do is get the image up to a certain required
size, pamcut may be what you want.

pamcut pnmcrop pnmcat pnm

Copyright (C) 1991 by Jef Poskanzer.

netpbm documentation 01 June 2002 Pnmmargin User Manual(0)