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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 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
   borders 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
          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 -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.

                             18 March 2001                      pnmcrop(1)



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