Deep Learning for Facial Action Unit Detection Under Large Head Poses

Abstract

Facial expression communicates emotion, intention, and physical state, and regulates interpersonal behavior. Automated face analysis (AFA) for the detection, synthesis, and understanding of facial expression is a vital focus of basic research with applications in behavioral science, mental and physical health and treatment, marketing, and human-robot interaction among other domains. In previous work, facial action unit (AU) detection becomes seriously degraded when head orientation exceeds $15^{\circ }$ to $20^{\circ }$ . To achieve reliable AU detection over a wider range of head pose, we used 3D information to augment video data and a deep learning approach to feature selection and AU detection. Source video were from the BP4D database (n = 41) and the FERA test set of BP4D-extended (n = 20). Both consist of naturally occurring facial expression in response to a variety of emotion inductions. In augmented video, pose ranged between $-18^{\circ }$ and $90^{\circ }$ for yaw and between $-54^{\circ }$ and $54^{\circ }$ for pitch angles. Obtained results for action unit detection exceeded state-of-the-art, with as much as a 10 % increase in $F_1$ measures.