A Multi-scale Feature Learning Network with Optical Flow Correction for Micro- and Macro-expression Spotting

Recently, automatic micro-expression (ME) analysis has attracted increasing attention, since ME is a spontaneous facial expression that can truly reflect the emotional state an individual tries to conceal. As a crucial step in ME analysis, Micro- and Macro-expression (MaE) spotting aims to sequentially identify the occurrence intervals of MEs and MaEs within a long video sequence. However, the subtle spatiotemporal movements of MEs and the scarcity of well-labeled data pose great challenges for accurately spotting them. To this end, this paper proposes a novel spotting framework based on Multi-scale Feature Learning Network with Optical Flow Correction. Specifically, we first integrate the pre-trained VideoMAE and customized convolutional layers as a visual feature extraction module to learn the facial motion features in long video sequences. Then, to comprehensively locate and identify the existing ME and MaE segments, we introduce a multi-scale candidate segment generation method based on the ActionFormer. In particular, a multi-start points optical flow filtering method is proposed to improve the precision of expression spotting. Finally, we conduct comprehensive experiments on the MEGC2024 spotting task, and the experimental results demonstrate the effectiveness of our method, which ranks second in this task. The implemented code is also publicly available at https://github.com/zzy188zzy/megc_spotting_code.