Automatic Detection and Recognition of Circular Road Sign

Road sign detection and recognition is an important research issue of driver assistance systems. This paper proposes a two-stage automatic detection and recognition algorithm for the most common road signs in China. In the first phase, color segmentation and Hough transform are used for ROI detection. Considering the difference between the actual road signs and standard road signs, the pictograph on road signs is extracted for recognition. Adaptive Hausdorff distance based on similarity weighting is employed in the recognition phase. The experiment results show the effectiveness for recognition and the insensitivity to slight occlusion.