Facial Motion Prior Networks for Facial Expression Recognition Deep learning based facial expression recognition (FER) has received a lot of attention in the past few years. Most of the existing deep learning based FER methods do not consider domain knowledge well, which thereby fail to extract representative features. In this work, we propose a novel FER framework, named Facial Motion Prior Networks (FMPN). Particularly, we introduce an addition branch to generate a facial mask so as to focus on facial muscle moving regions. To guide the facial mask learning, we propose to incorporate prior domain knowledge by using the average differences between neutral faces and the corresponding expressive faces as the training guidance. Extensive experiments on three facial expression benchmark datasets demonstrate the effectiveness of the proposed method, compared with the stateoftheart approaches.

Unpaired Images based Generator Architecture for Facial Expression Recognition Facial expression recognition (FER) is a challenging task due to the lack of sufficient training data. Most conventional approaches usually rotate or flip the images for data augmentation. More recently, numerous methods synthesize images automatically by using Generative Adversarial Network (GAN). However, paired images are always required in these methods. Different from existing methods, in this paper, we propose an endtoend deep learning model for simultaneous facial expression synthesis and facial expression recognition. In our method, paired images are not required, which makes the proposed model much more flexible and general. Furthermore, different expressions are encoded in a disentangled manner in a latent space, which enables us to generate facial images with arbitrary expressions by exchanging certain parts of their latent identity features. Finally, the facial expression synthesis and facial expression recognition tasks can further boost their performance for each other via our model. Quantitative and qualitative evaluations on both controlled and inthewild datasets demonstrate that the proposed method performs favorably against stateoftheart methods.