Ralph Lauren model Filippa Hamilton is glamorous, but is it physiologically possible for her
hips to be smaller than her head, as a recent ad showed? And how can
62-year-old supermodel Twiggy still look so fabulous? Digital touch-ups of celeb photos might fool someone quickly glancing at Cosmopolitan, or convince teen girls that Hamilton's 17-inch hips are
feasible. When pressed, however, humans are pretty good at telling when a body looks unnatural. To see if a computer could do the same, researchers
recruited 390 volunteers and asked them to look at 468 pairs of original and touched-up photos they had found online and rate each pair on a scale of
one to five on how altered they thought it was. The researchers then created a computer metric that measured parameters like color, blur, and cutting
of unsightly areas in the doctored photos. When they compared their metric's assessment of the photos against the volunteers' assessments, the two were
statistically similar, the researchers report in the Proceedings of the National Academy of Sciences today. A metric like this one, the
researchers hope, might help publishers weed out false advertisers.
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