Automatic and robust 3D face registration using multiresolution Spherical Depth Map

Face registration is a necessary preprocessing step for 3D face recognition. An entirely automatic method for 3D face registration is proposed in this paper with high accuracy and good robustness to pose and facial expression variations. Our method consists of the following three stages. Firstly, the face shape is represented by Fitting Sphere Representation (FSR). Secondly, generate the Spherical Depth Map (SDM) of face shape which is normalized roughly to a similar pose. Finally, accurately localize the nose tip using multiresolution SDM by a coarse-to-fine method. Then, in conjunction with the face orientation figured out by linear fitting and the center of fitting sphere, face can be registered completely. Extensive experiments are conducted on five popular 3D face databases. The registration accuracy is near 100 percent. Experimental results demonstrate the high robustness of the proposed methods to pose and expression variations.