Researchers claim they have perfected a system that uses computers to accurately identify images of people's faces, which could aid in the apprehension of criminals in public places such as airports that use surveillance cameras, according to a study released Thursday.
But some experts still doubt that facial recognition software can be used to accurately pick people out of crowded, public areas.
Comparing a database of images of criminals, to a real live person in a crowd, has been very difficult, concedes Rob Jenkins, a professor in the psychology department of the University of Glasgow and co-author of the study released in the journal Science.
But using a newly developed program at the university, computers were found to be 100 percent accurate when using what they call an "averaged" face image, made up of 20 photos, Jenkins and co-author Mike Burton wrote in the paper.
"The great thing about this averaging process is it just washes out all these differences of single photographs. The lighting and the pose all kind of becomes neutralized," Jenkins told ABCNEWS.com. And what you're just left with is the core of the face. The aspects of the image are consistent from one photo to the next."
Facial recognition programs have been used for years. The most successful applications have been in the government or the private sector, mostly to help identify employees seeking access to sensitive areas. Casinos have also been using the software to help spot criminals or known card cheats sitting at gaming tables.
That's a whole lot different then picking random people out of a moving crowd and matching the images to a datatbase of known criminals or terrorists, critics say.
"I'm skeptical that it will be able to show that there is 100 percent accuracy in facial recognition technology, especially in using facial recognition technology out of a crowd," said Melissa Ngo, director of the Identification and Surveillance Project at the Electronic Privacy Information Center. "We've seen any number of studies and examples when trying to use facial recognition technology itself has been completely flustered when the subject is not standing still or in the right light, looking right at the camera."
The Glasgow didn't begin as a study of facial recognition programs, Jenkins said. Instead, he and Burton were actually studying the way the human mind recognizes both familiar and unfamiliar faces in a series of photos.
"If you [show ] unfamiliar people two photographs, whether they show the same person or not, [they're] not reliable at all. The reason is two photos of the same face can be very, very different images. The face itself can change a good deal as we age, due to fluctuations in weight or health. Even more important, the ambient conditions that the photo is taken in can change," Jenkins said. "These kinds of things have a huge impact on the image the pattern of light and dark across the page, but they don't tell us anything about who the person is."
With familiar faces of friends and families and celebrities, however, Jenkins and Burton found that people easily recognized the faces, regardless of age, angle or light in which the photo was taken. Faces that were "averaged," or blended from several images into one, were even more recognizable and yielded even better results with human subjects.