Real time tracking of a remote moving object by active zoom cameras

Object detecting and tracking at a distance has been a big problem in the research field of wide area security. This paper introduces a real time active vision system which can track a moving object from 1 meter to 200 meters. This visual servo system is mainly structured of three mechanical freedoms of pan, tilt and zoom. An eagle's eye mechanism is proposed to obtain a wide field of view (FOV) in high resolution. A fusion schemes that combines the results of the three separate zoom cameras for detecting and tracking a moving object at distance is also developed. A high performance pan-tilt unit and an algorithm of high frequency motor control is proposed to smooth the tracking. This system has the tracking and zooming functions to monitor an unexpected object at a long distance. The camera can zoom in to capture the high resolution detail of a pedestrian and record a series of available images while tracking. In order to demonstrate the effectiveness of the approaches adopted, an experiment of tracking a pedestrian from a distance of 100–200 meters has been carried out. Experimental results show that the proposed system is valid for tracking a pedestrian at a distance.