Image.module original link on medium res image

I'm using image.module on my site. Here is an example of a node: http://adsoftheworld.com/media/print/volkswagen_coach

There is a link below the image that gives you the full size image (original size) that image module creates.

I would like to have the same link to be added to the image itself too, so readers would be able to click on the image to get the original image size rather than click the link below the image. How should I modify the image.module to achieve this?