Abstract: During tripline detection, Gauss model is used to model background, object is detected by background differencing. Scanning the set of points on the line, if object is detected, for doubledirection tripline detection, system directly alerts, but for singledirection tripline detection, the moving direction of the object must be analyzed first. If the moving direction of the object matches forbidden passing rule, system directly alerts. The experiment shows that the method can detect tripline event accurately. 〖JP〗

Key words: video surveillance, object detection, tripline detection