You can hide images url with php and ajax:
HTML:

<img id="image_id" src="" alt="" /> 

PHP File:

<?php
header('Content-Type: image/jpeg');
readfile('pathtoimage.jpg'); 
 ?>

Javascrip jQuery:

<script type="text/javascript">
	jQuery( document ).ready(function() {
jQuery('#image_id').attr('src', 'pathtophpfile.php'); });
</script>