Single-Side Domain Generalization for Face Anti-Spoofing

TL;DR

This paper introduces a novel single-side domain generalization framework for face anti-spoofing that enhances generalization across domains by learning a unified feature space for real faces while dispersing fake face features.

Contribution

The work proposes an end-to-end single-side adversarial learning approach with asymmetric triplet loss to improve face anti-spoofing generalization across diverse domains.

Findings

Outperforms state-of-the-art methods on four public databases.

Effectively separates real and fake face features across domains.

Enhances robustness to novel domain samples.

Abstract

Existing domain generalization methods for face anti-spoofing endeavor to extract common differentiation features to improve the generalization. However, due to large distribution discrepancies among fake faces of different domains, it is difficult to seek a compact and generalized feature space for the fake faces. In this work, we propose an end-to-end single-side domain generalization framework (SSDG) to improve the generalization ability of face anti-spoofing. The main idea is to learn a generalized feature space, where the feature distribution of the real faces is compact while that of the fake ones is dispersed among domains but compact within each domain. Specifically, a feature generator is trained to make only the real faces from different domains undistinguishable, but not for the fake ones, thus forming a single-side adversarial learning. Moreover, an asymmetric triplet loss is designed to constrain the fake faces of different domains separated while the real ones aggregated. The above two points are integrated into a unified framework in an end-to-end training manner, resulting in a more generalized class boundary, especially good for samples from novel domains. Feature and weight normalization is incorporated to further improve the generalization ability. Extensive experiments show that our proposed approach is effective and outperforms the state-of-the-art methods on four public databases.