<?php

$original = new Imagick();
$original->readImage(getcwd().'/example.jpg');

$original->setImageFormat('png');

$inverted = $original->clone();
$inverted->negateImage(true);

$original->compositeImage($inverted, Imagick::COMPOSITE_OVER, 0, 0);

header( "Content-Type: image/png" );
echo $original->getImageBlob();
 
?>