FPGA implementation of camera tamper detection in real-time

Video surveillance systems are becoming very common nowadays. Cameras installed in many places are exposed to sabotage or tampering. This can be done by covering the camera lens, changing the focus of the camera lens or changing the camera position to prevent proper registration of the surveilled area. This paper describes a hardware implementation of a system that can detect these kind of events. The algorithm is based on background modelling, histograms comparison, edges comparison and analysis of the image´s average brightness. In was described in a hardware description language in a pipeline manner and implemented in an FPGA device. Real-time processing of a video stream with a resolution of 640×480@60 frames per second was achieved. Tests performed on several sequences demonstrated the usefulness of the presented solution.