Financial services, the gig economy, telco, healthcare, social networking, and other customers use face verification during online onboarding, step-up authentication, age-based access restriction, and bot detection. These customers verify user identity by matching the user's face in a selfie captured by a device camera with a government-issued identity card photo or preestablished profile photo. They also estimate the user's age using facial analysis before allowing access to age-restricted content. However, bad actors increasingly deploy spoof attacks using the user's face images or videos posted publicly, captured secretly, or created synthetically to gain unauthorized access to the user's account. To deter this fraud, as well as reduce the costs associated with it, customers need to add liveness detection before face matching or age estimation is performed in their face verification workflow to confirm that the user in front of the camera is a real and live person.

Face anti-spoofing (FAS) aims at distinguishing face spoof attacks from the authentic ones, which is typically approached by learning proper models for performing the associated classification task. In practice, one would expect such models to be generalized to FAS in different image domains. Moreover, it is not practical to assume that the type of spoof attacks would be known in advance. In this paper, we propose a deep learning model for addressing the aforementioned domain-generalized face anti-spoofing task. In particular, our proposed network is able to disentangle facial liveness representation from the irrelevant ones (i.e., facial content and image domain features). The resulting liveness representation exhibits sufficient domain invariant properties, and thus it can be applied for performing domain-generalized FAS. In our experiments, we conduct experiments on five benchmark datasets with various settings, and we verify that our model performs favorably against state-of-the-art approaches in identifying novel types of spoof attacks in unseen image domains.