Use js prevent your browser of sending the referrer http header.
http://referrer-killer.googlecode.com/git/example.html
http://referrer-killer.googlecode.com/git/ReferrerKiller.js
<span id="image_kill_referrer"></span>
<script>
document.getElementById('image_kill_referrer').innerHTML = ReferrerKiller.imageHtml('http://img3.pixhost.org/images/2669/14341603_a_fun.jpg');
</script>