http://www.perlmonks.org?node_id=10635
Category: Utility scripts
Author/Contact Info Diego Zamboni
Description: This script allows you to select a portion of a postscript file and crop it. The whole file is included in the result, but the appropriate commands are included to crop it to the section you select. Instructions for use are included in the script.
#!/usr/local/perl/bin/perl
#
# Cropping a portion of a postscript file
# Postscript magic and instructions provided by Chapman Flack.
# Script implemented by Diego Zamboni <zamboni@cerias.purdue.edu>
#
# 1.  View the page in gv.  If it's a multipage document, mark the pag
+e and
#     hit "save marked" so you have a small file to deal with.
# 2.  Move the mouse pointer to the lower left corner of the area you 
+want.
#     Record the gv displayed coordinates as X1 and Y1.
# 3.  Point to the upper right corner and record X2 and Y2.
# 4.  Run "crop-ps X1 Y1 X2 Y2 file.ps > cropped_file.ps"
#
# This will not work for postscript files that do not have the appropr
+iate
# structuring comments (%%EndSetup, %%Page, etc.)

$usage="Usage: $0 x1 y1 x2 y2 file.ps";

$x1=shift @ARGV;
$y1=shift @ARGV;
$x2=shift @ARGV;
$y2=shift @ARGV;

($x1 && $y2 && $x2 && $y2 ) or
        die "$usage\n";

$w=$x2-$x1;
$h=$y2-$y1;

$flag=0;

while (<>) {
  if (/^%%BoundingBox:/) {
    print "%%BoundingBox: 0 0 $w $h\n";
  }
  elsif (!$flag && (/^%%EndSetup/ || /^%%Page:/)) {
    print;
    print "-$x1 -$y1 translate\n";
    print "$x1 $y1 moveto $x1 $y2 lineto $x2 $y2 lineto $x2 $y1 lineto
+ closepath\n";
    print "clip\n";
    $flag=1;
  }
  else {
    print;
  }
}