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


SYNOPSIS

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

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


DESCRIPTION

       Reads a 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,  top,
       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
              columns numbered from 0 at the left, increasing  to

              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, pnmcut 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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