A three-dimensional image of human faces can be constructed from flat 2-D images, a discovery that can be useful in security applications, U.S. researchers say.

Researchers at Florida Atlantic University say biometrics, the technology of performing personal identification or authentication using an individual's physical attributes, is becoming an increasingly viable solution for identity management, information protection and homeland security, a university release said Wednesday.

Researchers Xin Guan and Hanqi Zhuang have developed a computer algorithm that can analyze the viewing angle and illumination of a face in a flat image and generate a 3D view of the face based on the results.

They say that while faces are all different, they share so many characteristics it is difficult for current computer technology to uniquely identify an individual from a flat, two-dimensional image.

A processed 2D image that yields a 3D view of the face would give a unique perspective, the researchers say.

The technique could also be useful in forensic investigations, they say.

A 3D image of a person's face might be used in biometrics alongside or instead of fingerprint, iris, face, voice and DNA recognition techniques, the research findings published in the International Journal of Biometrics say.