#!/usr/bin/perl -w

use strict;

use Image::Magick;

my $image = Image::Magick->new;

$image->Read($ARGV[0]) && warn "$_";
$image->Set(magick=>'RGB');

my $rows = 6;
my $cols = 4;
my $boxsize = 50;

my @expected =
 ({name => "dark skin"    ,r => 106, g => 82,  b => 70}
 ,{name => "light skin"   ,r => 184, g => 146, b => 128}
 ,{name => "blue sky"     ,r => 101, g => 121, b => 153}
 ,{name => "foliage"      ,r => 95,  g => 107, b => 69}
 ,{name => "blue flower"  ,r => 128, g => 127, b => 173}
 ,{name => "bluish green" ,r => 129, g => 188, b => 171}
 ,{name => "orange"       ,r => 201, g => 123, b => 56}
 ,{name => "purplish blue",r => 77,  g => 91,  b => 166}
 ,{name => "moderate red" ,r => 173, g => 83,  b => 96}
 ,{name => "purple"       ,r => 86,  g => 60,  b => 104}
 ,{name => "yellow green" ,r => 166, g => 187, b => 75}
 ,{name => "orange yellow",r => 213, g => 160, b => 55}
 ,{name => "blue"         ,r => 49,  g => 65,  b => 143}
 ,{name => "green"        ,r => 99,  g => 148, b => 80}
 ,{name => "red"          ,r => 155, g => 52,  b => 59}
 ,{name => "yellow"       ,r => 227, g => 197, b => 52}
 ,{name => "magenta"      ,r => 169, g => 85,  b => 147}
 ,{name => "cyan"         ,r => 61,  g => 135, b => 167}
 ,{name => "white"        ,r => 245, g => 245, b => 245}
 ,{name => "neutral 8"    ,r => 200, g => 200, b => 200}
 ,{name => "neutral 6.5"  ,r => 161, g => 161, b => 161}
 ,{name => "neutral 5"    ,r => 120, g => 120, b => 120}
 ,{name => "neutral 3.5"  ,r => 84,  g => 84, b => 84}
 ,{name => "black"        ,r => 52,  g => 52, b => 52}
 );

my ($row,$col,$x,$y,$i,$j);
my $box = 0;
my ($rsum,$gsum,$bsum) = (0,0,0);

ROW: for($row=0;$row<$rows;$row++) {
   COL: for($col=0;$col<$cols;$col++,$box++) {
       my $x = 100 + $row*145;
       my $y = 100 + $col*145;
       for($i=$x;$i<$x+$boxsize;$i++) {
           for($j=$y;$j<$y+$boxsize;$j++) {
                my ($r,$g,$b,$o) = split(/,/,$image->Get("pixel[$i,$j]"));
                $_ = int($_/256) for ($r,$g,$b,$o);
                my $e = $expected[$box];
                if($i==$x && $j==$y) {
                    print $e->{'name'},"\n";
                    print "Expected:\tr: $e->{'r'}\tg: $e->{'g'}\t $e->{'b'}\n";
                    print "Actual  :\tr: $r\tg: $g\tb: $b\n";
                }
                $rsum += $r - $e->{'r'};
                $gsum += $g - $e->{'g'};
                $bsum += $b - $e->{'b'};
            }
        }
    }
}
my $samples = $boxsize * $boxsize * $rows * $cols;
my $rdiff = int ($rsum / $samples);
my $gdiff = int ($gsum / $samples);
my $bdiff = int ($bsum / $samples);

print "\nOverall Difference:\tr: $rdiff\tb: $bdiff\tg: $gdiff\n";

$image = Image::Magick->new;
$image->Read($ARGV[1]);
$image->Set(magick=>'RGB');
$image = $image->Fx(expression=>"1.0-r*($rdiff/255)",channel=>'red');
$image = $image->Fx(expression=>"1.0-g*($gdiff/255)",channel=>'green');
$image = $image->Fx(expression=>"1.0-b*($bdiff/255)",channel=>'blue');
unlink "out.jpg";
$image->Write("out.jpg");