A Speedy Way to Identify Victims
March 30, 2005Until recently forensic specialists often spent weeks building three-dimensional models to reconstruct the facial features of people that couldn't be identified any other way. Finger prints and DNA analysis sometimes won't help when dealing with decaying bodies, those found in mass graves or the remains of earth quake victims, for example.
Scientists at the Center for Advanced European Studies and Research (CAESAR) have now developed a new method to speed up the process. First, they create a layered model of the skull via c-scan. Using holography, they then add a layer of facial tissue on the computer, resulting in such a detailed model that victims can usually be identified with the help of this picture.
CAESAR experts developed a special face recognition software and make use of extensive, three-dimensional facial data sets. If a skull needs to be identified, scientists compare the skull with existing models to figure out which facial tissue will work best, according to Peter Hering, who heads the research unit.
If the facial tissue samples don't fit perfectly, Hering and his team use morphing techniques to adjust them to the skull. The technique also allows researchers to determine a person's ethnic background, age and sex.
Speeding up the process
Speed is the main advantage of this new method compared to the old way that required construction of a physical model, said Thorsten Buzug of Koblenz University of Applied Sciences, who also worked on the project.
"While forensic experts using conventional methods need three days to two weeks to create a facial model, the computer program allows us to create a face within an hour or two," he said.
Buzug added that the computer models are just as exact as the old ones, with the additional advantage of being able to alter them much more easily.
Scientists believe the new technique will be especially useful during catastrophic events, such as the South Asian tsunamis. They could also help to identify bodies found in mass graves in war-torn areas.
Other uses
But there are also other uses for the technique besides identifying bodies, Hering said.
"We had one case of a young woman, who fainted, fell on a hot plate and completely burnt half her face," he said, adding that the new program helped to reconstruct the woman's face.
Hering also said the technique allows people to see what they will look like after plastic surgery.