In the future forensic researchers could "harness" the human ability to recognize faces even from blurry or poor-quality images.
Faces are "the most commonly photographed object," a University of York news release reported.
Researchers may have found a way to "mine" through photos in order to turn the lens around and reveal the photographers face.
A research team found that by "zooming in on high-resolution passport-style photographs" they could get a glimpse of bystanders reflected in the eyes of the photo subjects. Observers were able to identify the figures taken from the eye-reflections despite the image's low resolution.
The team had study participants perform a number of "face matching tasks." Those who were unfamiliar with the faces in the images performed at about 71 percent accuracy; participants who were familiar with the faces performed at 84 percent accuracy. The test showed that in the case of "spontaneous recognition" participants could "reliably" identify a familiar face taken from a pupil reflection.
"The pupil of the eye is like a black mirror. To enhance the image, you have to zoom in and adjust the contrast. A face image that is recovered from a reflection in the subject's eye is about 30,000 times smaller than the subject's face. Our findings thus highlight the remarkable robustness of human face recognition, as well as the untapped potential of high-resolution photography," Doctor Rob Jenkins of the Department of Psychology at the University of York, said in the news release.
The team believes the technique could be used in identifying criminals in crimes such as "hostage taking or child sex abuse" where pictures are generally taken. Forensic experts could look for images of the photographer hidden in the victim's eyes. This system could also be efficient in cases where cameras are seized during criminal investigations.
