- Fraudulent photographs produced with powerful, commercial software appear constantly, spurring a new field of digital image forensics.
- Many fakes can be exposed because of inconsistent lighting, including the specks of light reflected from people’s eyeballs.
- Algorithms can spot when an image has a “cloned” area or does not have the mathematical properties of a raw digital photograph.
History is riddled with the remnants of photographic tampering. Stalin, Mao, Hitler, Mussolini, Castro and Brezhnev each had photographs manipulated—from creating more heroic-looking poses to erasing enemies or bottles of beer. In Stalin’s day, such phony images required long hours of cumbersome work in a darkroom, but today anyone with a computer can readily produce fakes that can be very hard to detect.
Barely a month goes by without some newly uncovered fraudulent image making it into the news. In February, for instance, an award-winning photograph depicting a herd of endangered Tibetan antelope apparently undisturbed by a new high-speed train racing nearby was uncovered to be a fake. The photograph had appeared in hundreds of newspapers in China after the controversial train line was opened with much patriotic fanfare in mid-2006. A few people had noticed oddities immediately, such as how some of the antelope were pregnant, but there were no young, as should have been the case at the time of year the train began running. Doubts finally became public when the picture was featured in the Beijing subway this year and other flaws came to light, such as a join line where two images had been stitched together. The photographer, Liu Weiqing, and his newspaper editor resigned; Chinese government news agencies apologized for distributing the image and promised to delete all of Liu’s photographs from their databases.