A Comprehensive Study on Center Loss for Deep Face Recognition

摘要

Deep convolutional neural networks (CNNs) trained with the softmax loss have achieved remarkable successes in a number of close-set recognition problems, e.g. object recognition, action recognition, etc. Unlike these close-set tasks, face recognition is an open-set problem where the testing classes (persons) are usually different from those in training. This paper addresses the open-set property of face recognition by developing the center loss. Specifically, the center loss simultaneously learns a center for each class, and penalizes the distances between the deep features of the face images and their corresponding class centers. Training with the center loss enables CNNs to extract the deep features with two desirable properties: inter-class separability and intra-class compactness. In addition, we extend the center loss in two aspects. First, we adopt parameter sharing between the softmax loss and the center loss, to reduce the extra parameters introduced by centers. Second, we generalize the concept of center from a single point to a region in embedding space, which further allows us to account for intra-class variations. The advanced center loss significantly enhances the discriminative power of deep features. Experimental results show that our method achieves high accuracies on several important face recognition benchmarks, including Labeled Faces in the Wild, YouTube Faces, IJB-A Janus, and MegaFace Challenging 1.