#!/usr/bin/perl
use warnings;
use strict;
use Image::Magick;

my $i1 = Image::Magick->new;
my $i2 = Image::Magick->new;

my $w = $i1->Read('image.png'); # read in images
warn("$w")  if $w;
exit  if $w =~ /^Exception/;

$w = $i2->Read( 'reference.png');
warn("$w")  if $w;
exit  if $w =~ /^Exception/;

$i1->Scale(width=>100, height=>100); # scale without preserving aspect ratio
$i2->Scale(width=>100, height=>100);

$w = $i1->Compare(image=>$i2);       # compare
die "$w" if $w;

printf "Errors is %f\n",     $i1->Get('error');
printf "Mean Error is %f\n", $i1->Get('mean-error');