[Chagrin]

#!/usr/bin/perl

use GD;

my $image = GD::Image->new("whatever.jpg");

my ($width, $height) = $image->getBounds();
foreach $x (0..$width) {
  foreach $y (0..$height) {
    my($red, $green, $blue) = $image->rgb($image->getPixel($x, $y));

    print "color is $red $green $blue at $x $y\n";
  }
}

Hey, that's the easy part.