#!/usr/bin/perl -w

use GD ;

# stuff
$type = $ARGV[0];
$srcfile = $ARGV[1];
$destfile = $ARGV[2];
%width = ('low'=>120.00,'med'=>550.00);

# open files
open(DEST,">$destfile") || die("$!");

# GD stuff
$in = newFromJpeg GD::Image($srcfile,1) || die("$!");

# determine target width,height
($srcwidth,$srcheight) = $in->getBounds() || die("$!");
$destheight = int($width{$type} * $srcheight / $srcwidth);
$destwidth = $width{$type};

$out = new GD::Image($destwidth,$destheight,1) || die("$!");

# render resize
$out->copyResampled($in,0,0,0,0,$destwidth,$destheight,$  srcwidth,$srcheight) || die("$!");

# write to file
print DEST $out->jpeg(100);
close DEST;

$ ./gdtest.pl low image.jpg thumbnail.jpg

Use of uninitialized value in multiplication (*) at gdtest.pl line 19.
Use of uninitialized value in subroutine entry at gdtest.pl line 25.
Inappropriate ioctl for device at gdtest.pl line 25.