One-Class Face Anti-spoofing via Spoof Cue Map-Guided Feature Learning
Authors: Pei-Kai Huang, Cheng-Hsuan Chiang, Tzu-Hsien Chen, Jun-Xiong Chong, Tyng-Luh Liu, Chiou-Ting Hsu

Many face anti-spoofing (FAS) methods have focused on learning discriminative features from both live and spoof training data to strengthen the security of face recognition systems. However since not every possible attack type is available in the training stage these FAS methods usually fail to detect unseen attacks in the inference stage. In comparison one-class FAS where the training data are from only live faces aims to detect whether a test face image belongs to the live class or not. In this paper we propose a novel One-Class Spoof Cue Map estimation Network (OC-SCMNet) to address the one-class FAS detection problem. Our first goal is to learn to extract latent spoof features from live images so that their estimated Spoof Cue Maps (SCMs) should have zero responses. To avoid trapping to a trivial solution we devise a novel SCM-guided feature learning by combining many SCMs as pseudo ground-truths to guide a conditional generator to generate latent spoof features for spoof data. Our second goal is to approximately simulate the potential out-of-distribution spoof attacks. To this end we propose using a memory bank to dynamically preserve a set of sufficiently "independent" latent spoof features to encourage the generator to probe the latent spoof feature space. Extensive experiments conducted on eight FAS benchmark datasets demonstrate that the proposed OC-SCMNet not only outperforms previous one-class FAS methods but also achieves comparable performances to state-of-the-art two-class FAS method. The codes are available at https://github.com/Pei-KaiHuang/CVPR24_OC_SCMNet.