Percentage difference between images: Difference between revisions

=={{header|C sharp|C#}}==

<lang Csharp>using System;

using System.Drawing;

class Program

{

static void Main()

{

Bitmap img1 = new Bitmap("Lenna50.jpg");

Bitmap img2 = new Bitmap("Lenna100.jpg");

if (img1.Size != img2.Size)

{

Console.Error.WriteLine("Images are of different sizes");

return;

}

float diff = 0;

for (int y = 0; y < img1.Height; y++)

{

for (int x = 0; x < img1.Width; x++)

{

Color pixel1 = img1.GetPixel(x, y);

Color pixel2 = img2.GetPixel(x, y);

diff += Math.Abs(pixel1.R - pixel2.R);

diff += Math.Abs(pixel1.G - pixel2.G);

diff += Math.Abs(pixel1.B - pixel2.B);

}

}

Console.WriteLine("diff: {0} %", 100 * (diff / 255) / (img1.Width * img1.Height * 3));

}

}</lang>

=={{header|Raku}}==

(formerly Perl 6)

<lang perl6>#!/usr/bin/env perl6

use v6;

use GD::Raw;

# Reference:

# https://github.com/dagurval/perl6-gd-raw

my $fh1 = fopen('./Lenna50.jpg', "rb") or die;

my $img1 = gdImageCreateFromJpeg($fh1);

my $fh2 = fopen('./Lenna100.jpg', "rb") or die;

my $img2 = gdImageCreateFromJpeg($fh2);

my $img1X = gdImageSX($img1);

my $img1Y = gdImageSY($img1);

my $img2X = gdImageSX($img2);

my $img2Y = gdImageSY($img2);

($img1X == $img2X and $img1Y == $img2Y) or die "Image dimensions must match.";

my $diff = 0;

my ($px1, $px2);

loop (my $i = 0; $i < $img1X; $i++) {

loop (my $j = 0; $j < $img1Y; $j++) {

$px1 = gdImageGetPixel($img1, $i, $j);

$px2 = gdImageGetPixel($img2, $i, $j);

$diff += abs(gdImageRed($img1, $px1) - gdImageRed($img2, $px2));

$diff += abs(gdImageGreen($img1, $px1) - gdImageGreen($img2, $px2));

$diff += abs(gdImageBlue($img1, $px1) - gdImageBlue($img2, $px2));

}

}

say "%difference = ", $diff/($img1X*$img1Y*3*255)*100;

gdImageDestroy($img1);

gdImageDestroy($img2);

</lang>

{{out}}

<pre>

%difference = 1.625593098

</pre>