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@pranid
Forked from akosnikhazy/compare-images-class
Last active January 24, 2023 07:01
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Compare two images with PHP
<?php
class compareImages
{
private function mimeType($i)
{
/*returns array with mime type and if its jpg or png. Returns false if it isn't jpg or png*/
$mime = getimagesize($i);
$return = array($mime[0],$mime[1]);
switch ($mime['mime'])
{
case 'image/jpeg':
$return[] = 'jpg';
return $return;
case 'image/png':
$return[] = 'png';
return $return;
default:
return false;
}
}
private function createImage($i)
{
/*retuns image resource or false if its not jpg or png*/
$mime = $this->mimeType($i);
if($mime[2] == 'jpg')
{
return imagecreatefromjpeg ($i);
}
else if ($mime[2] == 'png')
{
return imagecreatefrompng ($i);
}
else
{
return false;
}
}
private function resizeImage($i,$source)
{
/*resizes the image to a 8x8 squere and returns as image resource*/
$mime = $this->mimeType($source);
$t = imagecreatetruecolor(8, 8);
$source = $this->createImage($source);
imagecopyresized($t, $source, 0, 0, 0, 0, 8, 8, $mime[0], $mime[1]);
return $t;
}
private function colorMeanValue($i)
{
/*returns the mean value of the colors and the list of all pixel's colors*/
$colorList = array();
$colorSum = 0;
for($a = 0;$a<8;$a++)
{
for($b = 0;$b<8;$b++)
{
$rgb = imagecolorat($i, $a, $b);
$colorList[] = $rgb & 0xFF;
$colorSum += $rgb & 0xFF;
}
}
return array($colorSum/64,$colorList);
}
private function bits($colorMean)
{
/*returns an array with 1 and zeros. If a color is bigger than the mean value of colors it is 1*/
$bits = array();
foreach($colorMean[1] as $color){$bits[]= ($color>=$colorMean[0])?1:0;}
return $bits;
}
public function compare($a,$b)
{
/*main function. returns the hammering distance of two images' bit value*/
$i1 = $this->createImage($a);
$i2 = $this->createImage($b);
if(!$i1 || !$i2){return false;}
$i1 = $this->resizeImage($i1,$a);
$i2 = $this->resizeImage($i2,$b);
imagefilter($i1, IMG_FILTER_GRAYSCALE);
imagefilter($i2, IMG_FILTER_GRAYSCALE);
$colorMean1 = $this->colorMeanValue($i1);
$colorMean2 = $this->colorMeanValue($i2);
$bits1 = $this->bits($colorMean1);
$bits2 = $this->bits($colorMean2);
$hammeringDistance = 0;
for($a = 0;$a<64;$a++)
{
if($bits1[$a] != $bits2[$a])
{
$hammeringDistance++;
}
}
return $hammeringDistance;
}
}
?>
@NoBodyButMe
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@Casantana, just like this:

compare("test1.jpg", "test2.jpg"); ?>

@NoBodyButMe
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@Casantana... sorry, the chatbox dropped a line of code
It has to be

$c = new compareImages();
echo $c=>compare("test1.jpg", "test2.jpg");

@anand346
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anand346 commented Aug 2, 2022

what will it's return value

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