Is It Real?
Great article in the Times today on Doctored Photos. A few years back, one of my students was an expert witness on photographic images and we had many good discussions on the challenge of validating digital photographs. In court, he said a lawyer should never stipulate to a photographic print, only negatives BUT that the advent of digital photography was making it difficult to prove which photos were “real.”
Today’s article in the times is on two scientists, Hany Farid and Jessica Fridrich. Farid has developed an algorithm that can tell if photos might be doctored by checking for pixel averaging. His method works well on large TIFF files but needs work to be effective with the smaller JPEG format.
Fridrich has more of a forensic approach. Fridrich says that, like gun barrel markings, digital cameras have a “signature” that reveals which pictures were taken with them. Fridrich is designing a camera that photographs the shooters retina and embeds it with each photo for proof of who took it. The human retina is as individual as fingerprints. Does anyone else see an episode of CSI in the making? I think this is cool stuff!
