In detail, when the event rule is that none of the object can exist in the detection zone, the event detection procedure includes determining whether a coordinate of a detected object falls in the detection zone. Similarly, when the event rule is related to the dwell time or movement of one of the objects in the detection zone, and the coordinates of the object fall in the detection zone, the event detection procedure is performed based on the coordinates and a plurality of time points corresponding to the coordinates respectively, so as to determine the dwell time or movement of the detected object based on the coordinates and the plurality of time points.

After performing the event detection procedure in step S08, the computing device then outputs a detection result of the event detection procedure in step S10. Specifically, when the event detection procedure is performed to obtain the flow of the object in the detection zone (for example, traffic flow), the detection result preferably includes the object flow in the detection zone, or the abnormal activity of the object flow. In addition, the computing device can output the detection result to a storage device (for example, a memory) of the monitoring center for record, or to the display device for display, the present disclosure is not limited thereto.

When the behavior of the detected object does not meet the event rule, the computing device can output the detection result including a notification for the display device to display. On the contrary, when the computing device determines the behavior of the detected object meets the behavior rule in step S08, the camera sequentially acquires multiple images that are associated with the image acquiring scene in step S01 to update the detection zone.