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
    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 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
    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 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
    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.

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

AUTHOR
    Copyright (C) 1989 by Jef Poskanzer.