Images reflected in eyes of people photographed could be useful in forensic investigations

Scientists have found that photo portraits of an individual could yield images of the photographer or people standing close to the photographer.

The effort could be thought of as a foray into extreme facial recognition.

Even though the images appeared blurry when enhanced, they still carried enough detail to allow identification of the people reflected in the eyes of the subject.

A number of research teams have focused on the approach, called corneal imaging, which could potentially have a range of applications especially in criminal forensics and surveillance.

The approach also held potential for the reconstruction of the immediate environment that the subject of the photo occupied. Others included advanced computer graphics, facial and iris identification, and robotics, according to researchers.

The work mostly involves close-ups of the eye, and in addition sophisticated computer processing, to yield sharp reflected images.

However, according to Dr Rob Jenkins, with the University of York in the UK, and collaborator Christie Kerr at the University of Glasgow, useful images for identification of persons of interest in a crime did not have to be razor sharp, given the remarkable ability of humans to recognise patterns.

While looking at a close up of a subject's eye, the researchers were able to capture an image between 27 to 36 pixels wide by 42 to 56 pixels high showing the face of one of the "bystanders" they had organised to be in the subject's view.

They found that subjects could identify the image of people they already knew in the enlarged pupil reflection 84 per cent of the time.

When the person reflected was not known to them, they were able to identify them against a passport photo 71 per cent of the time.

According to Jenkins, the pupil of the eye was like a black mirror. He added, eyes in the photographs could reveal where one was and who one was with.

According to Jenkins, in the context of criminal investigations, this could be used to piece together networks of associates or to link individuals to particular locations.

The reflections could be especially useful in child abuse or kidnapping cases, where a victim was photographed by a criminal.

Though the photographs were taken with a high-end 29 pixel camera, the study's authors noted that as high-res cameras became more common in Smartphones, better images might become more readily available to police.