Vehicle window detection based on line features

Quickly and accurately locating vehicle windows will greatly improve efficiency of occupant detection in High-occupancy vehicle (HOV) system. Based on the fact that vehicle's windscreen has the geometric characteristics of line borders, a method involving frame difference, optimized edge detection and Hough transform to perform vehicle window detection is proposed. Experimental results have indicated that the proposed is effective for various vehicle type and color under different lighting conditions and backgrounds; and that its average executive time for each vehicle and success rate is 10~20ms and 95.4% respectively.