PointFace: Point Set Based Feature Learning for 3D Face Recognition

Though 2D face recognition (FR) has achieved great success due to powerful 2D CNNs and large-scale training data, it is still challenged by extreme poses and illumination conditions. On the other hand, 3D FR has the potential to deal with aforementioned challenges in the 2D domain. However, most of available 3D FR works transform 3D surfaces to 2D maps and utilize 2D CNNs to extract features. The works directly processing point clouds for 3D FR is very limited in literature. To bridge this gap, in this paper, we propose a light-weight framework, named PointFace, to directly process point set data for 3D FR. Inspired by contrastive learning, our PointFace use two weight-shared encoders to directly extract features from a pair of 3D faces. A feature similarity loss is designed to guide the encoders to obtain discriminative face representations. We also present a pair selection strategy to generate positive and negative pairs to boost training. Extensive experiments on Lock3DFace and Bosphorus show that the proposed PointFace outperforms state-of-the-art 2D CNN based methods.