Unsupervised Feature Disentanglement and Augmentation Network for One-class Face Anti-spoofing

Face anti-spoofing (FAS) techniques aim to enhance the security of facial identity authentication by distinguishing authentic live faces from deceptive attempts. While two-class FAS methods risk overfitting to training attacks to achieve better performance, one-class FAS approaches handle unseen attacks well but are less robust to domain information entangled within the liveness features. To address this, we propose an Unsupervised Feature Disentanglement and Augmentation Network (\textbf{UFDANet}), a one-class FAS technique that enhances generalizability by augmenting face images via disentangled features. The \textbf{UFDANet} employs a novel unsupervised feature disentangling method to separate the liveness and domain features, facilitating discriminative feature learning. It integrates an out-of-distribution liveness feature augmentation scheme to synthesize new liveness features of unseen spoof classes, which deviate from the live class, thus enhancing the representability and discriminability of liveness features. Additionally, \textbf{UFDANet} incorporates a domain feature augmentation routine to synthesize unseen domain features, thereby achieving better generalizability. Extensive experiments demonstrate that the proposed \textbf{UFDANet} outperforms previous one-class FAS methods and achieves comparable performance to state-of-the-art two-class FAS methods.

@article{huang2025_2503.22929,
  title={ Unsupervised Feature Disentanglement and Augmentation Network for One-class Face Anti-spoofing },
  author={ Pei-Kai Huang and Jun-Xiong Chong and Ming-Tsung Hsu and Fang-Yu Hsu and Yi-Ting Lin and Kai-Heng Chien and Hao-Chiang Shao and Chiou-Ting Hsu },
  journal={arXiv preprint arXiv:2503.22929},
  year={ 2025 }
}