PHP fast image compare lib. Get hash string and detect duplicate image
$image1 = 'image1.jpg';
$image2 = 'image2.jpg';
$compareMachine = new compareImages($image1);
$diff = $compareMachine->compareWith($image2);
$image2Hash = $compareMachine->hasStringImage($image2);
$diff = $compareMachine->compareHash($image2Hash);
If($diff<11){
echo 'Duplicate Image';
}
else{
echo '2 different image';
}