What's real and what's phony?
Dartmouth News - Investigating digital images - 07/01/04
"Seeing is no longer believing. Actually, what you see is largely irrelevant," says Dartmouth Professor Hany Farid. He is referring to the digital images that appear everywhere: in newspapers, on Web sites, in advertising, and in business materials, for example.
Farid and Dartmouth graduate student Alin Popescu have developed a mathematical technique to tell the difference between a "real" image and one that's been fiddled with. Consider a photo of two competing CEOs talking over a document labeled "confidential - merger," or a photo of Saddam Hussein shaking hands with Osama bin Laden. The Dartmouth algorithm, presented recently at the 6th International Workshop on Information Hiding, in Toronto, Canada, can determine if someone has manipulated the photos, like blending two photos into one, or adding or taking away objects or people in an image.