A motion-based framework for real-time anomaly detection in crowded scenes
摘要
Detecting abnormal behavior in crowded scenes is a critical yet challenging task in intelligent video surveillance due to complex motion patterns, occlusions, and dynamic interactions. To address these challenges, this paper proposes a lightweight, real-time motion-based framework for anomaly detection that does not require data-intensive training. The proposed approach utilizes dense optical flow estimation based on the Farneback algorithm, followed by temporal filtering, adaptive pixel-level motion segmentation, and a novel spatial energy distribution model to enhance anomaly localization. Additionally, an adaptive thresholding mechanism and region-level majority voting are employed to improve detection robustness and reduce false alarms. The framework was evaluated on two benchmark datasets: the UMN dataset and the HAJJv2 dataset, which represent controlled and real-world crowded environments, respectively. Experimental results demonstrate that the proposed method achieves 99.4% accuracy and an mAP of 0.96 on the UMN dataset, and 90.13% accuracy with an mAP of 0.93 on the HAJJv2 dataset, outperforming several state-of-the-art approaches while maintaining real-time performance (28 FPS). These results confirm that the proposed framework provides an effective, interpretable, and computationally efficient solution for anomaly detection in crowded scenes, making it well-suited for deployment in safety-critical surveillance applications.