Early in his career, Southern politician John Calhoun was a strong supporter of slavery. So it is ironic that an iconic portrait of Abraham Lincoln (circa 1860) is a photographic composite of Calhoun's body and Lincoln's head, purportedly created because no sufficiently heroic-style portrait of Lincoln had yet been taken. Perhaps what is most remarkable about this composite is that it was created only a few decades after Joseph Nicephore Niepce created the first permanent photograph in the summer of 1826. Although we may have the impression that photographic tampering is something relatively new - a product of the digital age - the reality is that history is riddled with photographic fakes.
Hany Farid, the David T. McLaughlin Distinguished Professor of Computer Science at Dartmouth College, has pioneered the field of digital image forensics.