The Hidden Photos Within Photos

Imagine you’re partying with some friends, and you take a photo of the group. Everyone is having a good time, drinking, smoking, etc. You want to post the photo to your Flickr, MySpace or Facebook account, but think maybe you should crop out the face of your friend who was smoking pot in the photo, since you don’t want to get him in trouble. Well, depending on your camera and software used to crop the photo, there’s a good chance someone downloading that photo from your website might find his face afterall.

Ryan Singel points Tonu Samuel’s demonstration of some cameras that also embed a small thumbnail image of the original photo that can survive subsequent tinkering and cropping – allowing a before-and-after comparison. He’s written a web crawler that’s collecting images with hidden thumbnails, and displaying both the final image and the uncensored thumbnail on his website.

Most of the comparisons are just minor cropping or tweaking for aesthetics, but some reveal the faces of, um, boudoir photographs that had been obscured when originally posted to the web. Some, like the samples here, zoom in on one subject, losing the context of the full situation: is he looking smug as she laughs hysterically, or is she crying? Or is she covering her face because she doesn’t want it to be known she was with him at that particular moment?
Its not too hard to imagine the growing wave of MySpace & Facebook forensic investigations taking advantage of this kind of meta data hidden within the photos posted to the web.