Weakly-Supervised Facial Expression Recognition in the Wild With Noisy Data
Feifei Zhang, Mingliang Xu, Changsheng Xu
Abstract
Facial expression recognition (FER) has attracted much attention in recent years due to its wide applications. While some progress has been achieved thanks to the emergence of deep learning, the challenge occasioned by pose variations remains. Therefore, most conventional approaches mainly perform FER under laboratory-controlled environment, and the FER in-the-wild has received relatively less attention. To implement the FER in-the-wild, the pose-invariant expression recognition model would be a possible solution but for a paucity of training data. Sufficient training data with reliable expression labels on FER tasks typically are unavailable. This paper devotes to addressing the problem of how to model pose variations in facial images, and how to leverage noisy data in the web to boost the FER performance. The proposed model is implemented in an end-to-end weakly supervised manner and enjoys several merits. First, the proposed model utilizes massive noisy labeled data to boost the performance of the FER classifier trained on a small set of clean labels. Second, we offer a novel pose modeling network to adaptively capture the discrepancy in the deep representation space of facial images under different head poses, and consequently, the pose-invariant expression representations can be learned in our model. Last, to exploit the reliable information in the noisy data, we formulate a noise modeling network, which is capable of learning the mapping from feature space to the residuals between clean labels and noisy labels. We validate the proposed approach on four public FER benchmarks: AffectNet, RAF-DB, SFEW, and BU-3DFE. Extensive experiments show that the proposed method performs favorably against state-of-the-art methods.