Psychophysical evaluation of animated facial expressions

The human face is capable of producing an astonishing variety of expressions - expressions for which sometimes the smallest difference changes the perceived meaning noticably. Producing realistic-looking facial animations that are able to transport this degree of complexity continues to be a challenging research topic in computer graphics. One important question that remains to be answered is: When are facial animations good enough? Here we present an integrated framework in which psychophysical experiments are used in a first step to systematically evaluate the perceptual quality of computer-generated animations with respect to real-world video sequences. The result of the first experiment is an evaluation of several animation techniques in which we expose specific animation parameters that are important for perceptual fidelity. In a second experiment we then use these benchmarked animations in the context of perceptual research in order to systematically investigate the spatio-temporal characteristics of expressions. Using such an integrated approach, we are able to provide insights into facial expressions for both the perceptual and computer graphics community.