Track detecting method of moving objects based on partial gravity center synthesis

摘要

The movement of an object can be detected by subtracting the successive two frames of the object's video sequence. On the image after subtraction, there is a larger difference in the object area while a smaller one in the background part. So the track of a moving object can be detected by calculating the position of its gravity center on the image. But if there are several moving objects or the background is moving too, the gravity center of the image is not the real one of any objects. In this paper, we divided the image into 16 X 16=256( or 32 X 32=1024 )parts and calculate the gravity center of each one. Then we get rid of parts with small average weight according to a certain threshold. The parts belong to the same moving object should be grouped in space, and a new gravity center is obtained. It is quite easy to get rid of the parts belong to the background because their differences are small and their moving vector are same. On the condition of 768X576 resolution and 25f/s video frequency, we are able to detect the tracks of several moving objects against a moving background and display them on a PC screen in real time.