Facial expressions (FEs) and action units (AUs) are facial emotional representations at different levels of granularity. In the past, recognizing them has often been treated as two separate tasks. There are also some methods that use the knowledge of one to aid in recognizing the other, but currently, unified models capable of recognizing both FEs and AUs simultaneously remain rare. In this paper, we construct a unified model with strong generalization capability to jointly perform facial expression recognition (FER) and action unit detection (AUD). Considering the extremely limited training samples annotated with both FEs and AUs, we introduce a large amount of unlabeled facial data from the wild. We carefully design category-specific confidence margins and leverage the correspondences between FEs and AUs to assign credible pseudo-labels to the unlabeled facial data. Furthermore, we incorporate semantically richer textual descriptions as supervision and refine them through visual perception, leveraging the inherent correlations between AUs and between FEs and AUs to enhance their precision. Extensive experiments demonstrate the superiority of the proposed method from various perspectives, including a unified zero-shot benchmark for exploring the model's comprehensive generalization capability to recognize facial emotional representations across multiple datasets, as well as within-domain and cross-domain evaluations after fine-tuning. The code for the proposed method is available at https://github.com/yuankaishen2001/MGFER.
Yuan et al. (Thu,) studied this question.