Recovering 3D facial shape from a single image

In this paper, we propose an improved method for recovering 3D facial shape from a single image. We use level set method to solve the Eikonal equation obtained from the method of shape from shading (SFS). However, the results are not usually usable due to the concave-convex ambiguity problems inherent to SFS. In order to overcome the concave-convex ambiguities of SFS, we find out the boundary of the concave-convex ambiguities according to the flatness of the triangle faces, and then we use the energy minimization method to recover the accuracy facial shape.