pnmcrop(1) - man - phpman

Che Dong

⚡ TLDR: pnmcrop (tldr-pages)

Crop PNM images.

Remove white borders on a PNM image
pnmcrop {{-w|-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}} {{-t|-top}} {{-l|-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 behavior if the image is entirely made out of background
pnmcrop {{-m|-margin}} {{n}} {{-blan|-blank-image}} {{pass|minimize|maxcrop}} {{path/to/image.pnm}} > {{path/to/output.pnm}}

pnmcrop(1) General Commands Manual pnmcrop(1)

NAME
pnmcrop - crop a portable anymap

SYNOPSIS
pnmcrop [-white|-black|-sides] [-left] [-right] [-top] [-bottom] [pnmfile]

All options may be abbreviated to their shortest unique prefix or specified with double hy‐
phens.

DESCRIPTION
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 mid‐
way 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 -bot‐‐
tom options.

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 pnmcomp.

OPTIONS
-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 fol‐
lowing order, taking the first found as the background color: top, left, right, bot‐
tom. 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
-sides.

-left Remove any left border.

-right Remove any right border.

-top Remove any top border.

-bottom
Remove any bottom border.

-verbose
Print on Standard Error information about the processing, including exactly how much
is being cropped off of which sides.