Image of the week - Facevision

Photo courtesy Geometrix FaceVision

In this era of closed-circuit televisions, surveillance cameras and cell phone cameras, the chances are great that a criminal or a terrorist has been photographed at some point while committing a crime (or shortly before or after). But it can be hard to definitely identify someone, and even eyewitness testimony can be suspect.

But authorities have a new tool: facial recognition software. Software services such as Geometrix FaceVision use quantitative means to compare two facial images, taking millions of measurements of dozens of “landmarks” and unusual features to come up with a match. It can be a numerically complex challenge, as even a small change in pose angle results in an alteration of the distances measured between facial features. Many diffent images, and many calculations, are needed to come up with a  texture-mapped, rotatable, 3-D surface of a face.