  In this paper, we present a novel approach to automatic 3D Facial Expression
Recognition (FER) based on deep representation of facial 3D geometric and 2D
photometric attributes. A 3D face is firstly represented by its geometric and
photometric attributes, including the geometry map, normal maps, normalized
curvature map and texture map. These maps are then fed into a pre-trained deep
convolutional neural network to generate the deep representation. Then the
facial expression prediction is simplyachieved by training linear SVMs over the
deep representation for different maps and fusing these SVM scores. The
visualizations show that the deep representation provides a complete and highly
discriminative coding scheme for 3D faces. Comprehensive experiments on the
BU-3DFE database demonstrate that the proposed deep representation can
outperform the widely used hand-crafted descriptors (i.e., LBP, SIFT, HOG,
Gabor) and the state-of-art approaches under the same experimental protocols.
