Hierarchical Scene Normality-Binding Modeling for Anomaly Detection in Surveillance Videos

Anomaly detection in surveillance videos is an important topic in the multimedia community, which requires efficient scene context extraction and the capture of temporal information as a basis for decision. From the perspective of hierarchical modeling, we parse the surveillance scene from global to local and propose a Hierarchical Scene Normality-Binding Modeling framework (HSNBM) to handle anomaly detection. For the static background hierarchy, we design a Region Clustering-driven Multi-task Memory Autoencoder (RCM-MemAE), which can simultaneously perform region segmentation and scene reconstruction. The normal prototypes of each local region are stored, and the frame reconstruction error is subsequently amplified by global memory augmentation. For the dynamic foreground object hierarchy, we employ a Scene-Object Binding Frame Prediction module (SOB-FP) to bind all foreground objects in the frame with the prototypes stored in the background hierarchy according their positions, thus fully exploit the normality relationship between foreground and background. The bound features are then fed into the decoder to predict the future movement of the objects. With the binding mechanism between foreground and background, HSNBM effectively integrates the "reconstruction" and "prediction" tasks and builds a semantic bridge between the two hierarchies. Finally, HSNBM fuses the anomaly scores of the two hierarchies to make a comprehensive decision. Extensive empirical studies on three standard video anomaly detection datasets demonstrate the effectiveness of the proposed HSNBM framework.