Facial Expression Recognition Integrating Multi-Stage Feature Sparse Constraints and Key Region Graph Learning

Current Facial expression recognition methods typically extract facial features indiscriminately, incorporating expression-irrelevant information that compromises recognition accuracy. To overcome this, we propose Multi-stage Feature Sparse Constraints (MFSC), a novel model that integrates a Multi-scale Attention-based Sparse Window Selection (MSAWS) mechanism with key region graph learning. Notably, MFSC operates without dependence on pre-extracted facial landmarks, enabling more flexible deployment. The MSAWS mechanism progressively filters redundant features through multi-stage sparse attention, adaptively selecting the most discriminative facial patches. The selected tokens are structured into a dynamic graph to model regional relationships via graph neural networks (GNNs). Critically, our framework further introduces a global-guided fusion module, which effectively integrates fine-grained local features from an IR50 backbone with the global topological features from the GNN through cross-attention. This integration enables complementary strengths, where local details are enhanced by global semantic context. Comprehensive experiments on RAF-DB, FER2013, and AffectNet-7 datasets demonstrate MFSC’s superior performance, achieving state-of-the-art accuracy of 92.31%, 76.21%, and 67.35%, respectively. These results validate the effectiveness of our approach in focusing computational resources on expression-salient regions while maintaining a lightweight and efficient architecture.