phpman > man > pamcut(1)

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 bottomrow] [-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 options.  Options are eas‐
       ier 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 specifications 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 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, re‐
       spectively.  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 posi‐
       tive, 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.

       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 num‐
              ber, 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, 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 un‐
              less 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
              dimensions 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)