Dynamic Objectives Learning for Facial Expression Recognition

Facial expression recognition has been widely used to solve the problems such as lie detection and human-machine interaction. However, due to the difficulties to control the application environments, current methods have the lower recognition accuracy in practice. This paper proposes a new method for facial expression recognition by considering several aspects. First, human beings are easy to recognize some expressions, while difficult to recognize others. Inspired by this intuition, a new loss function is proposed to enlarge the distances between samples from easily confused categories. Second, human learning is divided into many stages, and the learning objective of each stage is different. Thus, dynamic objectives learning is proposed, where each objective at different stage is defined by the corresponding loss function. In order to better realize the above ideas, a new deep neural network for facial expression recognition is proposed, which integrates the covariance pooling layer and residual network units into the deep convolution neural network so as to better perform dynamic objectives learning. The experimental results on the standard databases verify the effectiveness and the superior performance of our methods.