pnmcrop

pnmcrop(1)                  General Commands Manual                 pnmcrop(1)

NAME
       pnmcrop - crop a portable anymap

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

       All options may be abbreviated to their shortest unique prefix or spec-
       ified with double hyphens.

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  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  in-
       stead 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  bor-
       ders with the -left, -right, -top, and -bottom options.

       If you want to chop a specific amount off the side of an image, use pn-
       mcut.

       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 cor-
              ners 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, pnm-
              crop 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,  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 im-
              age  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,  in-
              cluding exactly how much is being cropped off of which sides.

SEE ALSO
       pnmcut(1), pnmfile(1), pnm(5)

AUTHOR
       Copyright (C) 1989 by Jef Poskanzer.

                                 18 March 2001                      pnmcrop(1)