Abstract:To address missed and false detections caused by scale compression, frequent occlusion, and short-duration weak-dynamic interaction behaviors under top-view surveillance conditions in unmanned retail stores, a customer behavior detection method for complex environments was studied. A constrained Ghost Convolution (GhostConv) structure was introduced into the mid-to-high layers of the You Only Look Once version 8 (YOLOv8) backbone. A direction-aware attention module was embedded into the high-semantic feature layers of the feature pyramid network. The Minimum Point Distance Intersection over Union (MPDIoU) loss was adopted to optimize bounding box regression. Spatially aligned human feature sequences generated by the detection stage were used as input. A lightweight Temporal Convolutional Network based on dilated causal convolutions was constructed, and a controlled temporal receptive field was designed for short-term behavior modeling. Experimental results on UCF101, HMDB-51, and a self-built unmanned retail dataset show that the proposed method improves behavior detection accuracy and stability under complex top-view and occlusion conditions, meeting the application requirements of customer behavior detection in unmanned retail stores.