German technology re-creates faces

Forensic experts and plastic surgeons should be interested in this technology: A group of German scientists have developed a method to reconstruct faces by using holograms to build three-dimensional models.

Until now, forensic experts have often spent weeks building three-dimensional models in clay or wax to reconstruct the facial features of people who couldn't be identified any other way, while plastic surgeons have had to rely on two-dimensional models for reconstructing faces either born with defects or badly malformed from tumors or accidents.

Scientists at the Center for Advanced European Studies and Research (Ceasar) in Bonn, Germany, now have a method that promises not only to speed up the process of re-creating faces but also to make it more accurate. The method uses a mix of technologies, including computer tomography (CT), holography, rapid prototyping and special face recognition software.

First, the researchers make a CT-scan of the skull and generate a three-dimensional data set. Then they make a hologram of the face, using an ultra-fast "pulse" holographic camera to image the surface of its soft tissue. The three-dimensional data sets from the two analyses are then merged and, with the help of a rapid prototyping technique borrowed from the engineering industry, are used to create a virtual three-dimensional replica of a head with facial tissue. A layer of skin can be added or removed directly on the computer screen with the help a morphing application.

"The problem with creating a three-dimensional data set of soft skin tissue from living people is that you need a very high exposure," says Peter Hering, a physicist at the University of D