pnmcrop - crop a portable anymap
pnmcrop [-white|-black|-sides] [-left] [-right] [-top] [-bottom] [pnmfile]
All options may be abbreviated to their shortest unique prefix or specified with double
Reads a PBM, PGM, or PPM image as input. Removes borders that are the background color,
and produces the same type of image as output.
If you don't specify otherwise, pnmcrop assumes the background color is whatever color the
top left and right corners of the image are and if they are different colors, something
midway between them. You can specify that the background is white or black with the
-white and -black options or make pnmcrop base its guess on all four corners instead of
just two with -sides.
By default, pnmcrop chops off any stripe of background color it finds, on all four sides.
You can tell pnmcrop to remove only specific borders with the -left, -right, -top, and
If you want to chop a specific amount off the side of an image, use pnmcut.
If you want to add different borders after removing the existing ones, use pnmcat or pnm-
-white Take white to be the background color. pnmcrop removes borders which are white.
-black Take black to be the background color. pnmcrop removes borders which are black.
-sides Determine the background color from the colors of the four corners of the input
image. pnmcrop removes borders which are of the background color.
If at least three of the four corners are the same color, pnmcrop takes that as the
background color. If not, pnmcrop looks for two corners of the same color in the
following order, taking the first found as the background color: top, left, right,
bottom. If all four corners are different colors, pnmcrop assumes an average of
the four colors as the background color.
The -sides option slows pnmcrop down, as it reads the entire image to determine the
background color in addition to the up to three times that it would read it without
-left Remove any left border.
-right Remove any right border.
-top Remove any top border.
Remove any bottom border.
Print on Standard Error information about the processing, including exactly how
much is being cropped off of which sides.
pnmcut(1), pnmfile(1), pnm(5)
Copyright (C) 1989 by Jef Poskanzer.
18 March 2001 pnmcrop(1)