pamcut

pamcut(1)                   General Commands Manual                  pamcut(1)

NAME
       pamcut - cut a rectangle out of a PAM, PBM, PGM, or PPM image

SYNOPSIS
       pamcut [-left leftcol] [-right rightcol] [-top toprow] [-bottom bottom-
       row] [-width width] [-height height] [-pad]  [-verbose]  [  left  right
       width height ] [pnmfile]

       All options may be abbreviated to the shortest unique prefix.

DESCRIPTION
       Reads  a  PAM, PBM, PGM, or PPM image as input.  Extracts the specified
       rectangle, and produces the same kind of image as output.

       There are two ways to specify the rectangle to cut: arguments  and  op-
       tions.   Options  are easier to remember and read, more expressive, and
       allow you to use defaults.  Arguments were the only way  available  be-
       fore July 2000.

       If you use both options and arguments, the two specifications get mixed
       in an unspecified way.

       To use options, just code any mixture of the -left, -right, -top, -bot-
       tom, -width, and -height options.  What you don't specify defaults.  It
       is an error to overspecify, i.e. to specify all three of -left, -right,
       and -width or -top, -bottom, and -height.

       To  use  arguments,  specify  all  four  of the left, right, width, and
       height arguments.  left and top have the same effect as specifying them
       as  the  argument  of  a -left or -top option, respectively.  width and
       height have the same effect as specifying them as  the  argument  of  a
       -width or -height option, respectively, where they are positive.  Where
       they are not positive, they have the same effect as specifying one less
       than  the  value as the argument to a -right or -bottom option, respec-
       tively.  (E.g.  width = 0 makes the cut go all the  way  to  the  right
       edge).   Before  July 2000, negative numbers were not allowed for width
       and height.

       Input is from Standard Input if you don't specify the input  file  pnm-
       file.

       Output is to Standard Output.

       If  you  are  splitting  a single image into multiple same-size images,
       pamdice is faster than running pamcut multiple times.

OPTIONS
       -left  The column number of the leftmost column to be  in  the  output.
              If a nonnegative number, it refers to columns numbered from 0 at
              the left, increasing to the right.  If negative,  it  refers  to
              columns numbered -1 at the right, decreasing to the left.

       -right The  column  number of the rightmost column to be in the output,
              numbered the same as for -left.

       -top   The row number of the topmost row to be in  the  output.   If  a
              nonnegative number it refers to rows numbered from 0 at the top,
              increasing downward.  If negative, it refers to columns numbered
              -1 at the bottom, decreasing upward.

       -bottom
              The  row number of the bottom-most row to be in the output, num-
              bered the same as for -top.

       -width The number of columns to be in the output.  Must be positive.

       -height
              The number of rows to be in the output.  Must be positive.

       -pad   If the rectangle you specify is not entirely  within  the  input
              image, pamcut fails unless you also specify -pad.  In that case,
              it pads the output with black up to the edges you specify.   You
              can  use this option if you need to have an image of certain di-
              mensions and have an image of arbitrary dimensions.

              pnmpad also adds borders to an  image,  but  you  specify  their
              width directly.

       -verbose
              Print information about the processing to Standard Error.

SEE ALSO
       pnmcrop(1), pnmpad(1), pnmcat(1), pgmslice(1), pnm(5)

AUTHOR
       Copyright (C) 1989 by Jef Poskanzer.

                                03 August 2000                       pamcut(1)