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


SYNOPSIS

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

       All options may be abbreviated to the shortest unique pre­
       fix.


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: argu­
       ments and options.  Options are  easier  to  remember  and
       read,  more  expressive,  and  allow  you to use defaults.
       Arguments were the only way available before July 2000.

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

       To  use  options,  just  code  any  mixture  of the -left,
       -right, -top, -bottom, -width, and -height options.   What
       you  don't  specify defaults.  It is an error to overspec­
       ify, 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, respectively.  (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 pnmfile.

       Output is to Standard Output.


OPTIONS

       -left  The  column  number of the leftmost column to be in
              the output.  If a nonnegative number, it refers  to

              the right.  If negative, it refers to columns  num­
              bered -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 out­
              put.   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, numbered 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 spec­
              ify  -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
              dimensions and have an image  of  arbitrary  dimen­
              sions.

              pnmpad also adds borders to an image, but you spec­
              ify 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.


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