If i have lots of images appearing tumblr blogs, the sort of tumblogs with very little text just reams and reams of images for people to browse through (example - http://whereisthecool.com/). If my image is embeded in their site like this :

<a href="http://mysite.com" target="blank">

<img src="cutecatblog.com/cat.jpg" alt="cute cat"/>

</a>

so the image was a link back to my site. Although there is no anchor text to speak of does google take into account the alt text of the image ?

Would this still count in googles eyes as a backlink ?