Changing faces

2019-03-07 06:07:01

By Catherine Zandonella in Los Angeles EVEN the Mona Lisa’s mysterious smile can be turned into a frown thanks to a new way of “morphing” faces. German computer scientists say they can turn two-dimensional photographs into three-dimensional faces, alter facial expressions, and even make faces fatter or thinner. Human faces are notoriously difficult to model on screen because they come in so many shapes and sizes. Current morphing methods rely on matching up corresponding features, such as the tip of the nose, the corner of the eye and prominent points on the cheek between two or more separate faces. But this is not always accurate, so it can result in unrealistic faces. But the technique researchers are developing at the Max Planck Institute in Tübingen appears to solve this problem. They scanned the faces of 200 postgraduates into their database. Half the volunteers were male and half female. Each scanned face contains several thousand data points—far more than the hundred or so used in existing methods. By combining these faces, the researchers can build a “prototype” face, analogous to averaging all 200. The prototype is their starting point for creating other faces. Besides adjusting the size and shape of the main features, you can use a sliding bar to add weight to the face, make the face look more masculine or feminine, or make the mouth smile or frown. “The novelty of this idea is that we took a learning-based approach, in that we used existing faces to derive the characteristics of faces,” says Thomas Vetter, who created the model with Volker Blanz, both at the Max Planck Institute’s Center for Biological Cybernetics. Because it was created from scans of German students, however, it can only create Caucasian faces between the ages of about 15 and 40. “It will be an interesting technique down the line,” says Rod Bogart, a computer graphics software developer at Industrial Light and Magic,