Fast and Light Manifold CNN based 3D Facial Expression Recognition across Pose Variations

Abstract

This paper proposes a novel approach to 3D Facial Expression Recognition (FER), and it is based on a Fast and Light Manifold CNN model, namely FLM-CNN. Different from current manifold CNNs, FLM-CNN adopts a human vision inspired pooling structure and a multi-scale encoding strategy to enhance geometry representation, which highlights shape characteristics of expressions and runs efficiently. Furthermore, a sampling tree based preprocessing method is presented, and it sharply saves memory when applied to 3D facial surfaces, without much information loss of original data. More importantly, due to the property of manifold CNN features of being rotation-invariant, the proposed method shows a high robustness to pose variations. Extensive experiments are conducted on BU-3DFE, and state-of-the-art results are achieved, indicating its effectiveness.