参考[ArcFace: Additive Angular Margin Loss for Deep Face Recognition](https://arxiv.org/abs/1801.07698)
备注:上述模型训练使用的loss_type为'dist_arcface'。更多关于ArcFace的内容请参考[ArcFace: Additive Angular Margin Loss for Deep Face Recognition](https://arxiv.org/abs/1801.07698)