Contao Image-Prozessing for responsive images

gistfile1.php

<?php 
	$this->import('Environment');
	$ua = $this->Environment->agent; // Import User Agent class

	// check if agent is mobile
	if($ua->mobile) {
		$image_link = $arrItem['raw']['picture']; // load picture url
		$image = $this->getImage($image_link,1024,768,'proportional'); // create thumb  $link, $w,$h,$cropmode
	}
				
	// if not, deliver the full picture
	else {
  		$image = $arrItem['raw']['picture'];
	}
?>