Model-based estimation of facial expression parameters from image sequences

We present a model-based algorithm for the estimation of 3D motion and the analysis of facial expressions of a speaking person. A set of facial animation parameters based on the MPEG-4 standard is determined from two successive video frames using a hierarchical optical flow based method. The motion in the image plane is constrained by a 3D triangular B-spline model that defines shape, texture and facial expressions of an individual person. The computational requirement for this solution is low due to the linear structure of the algorithm.