New method for recognition of circular traffic sign based on radial symmetry and pseudo-zernike moments

Recognizing various traffic signs, especially the popular circular traffic signs, is an essential task for implementing advanced driver assistance system. To recognize circular traffic signs with high accuracy and robustness, a novel approach which uses the so-called improved constrained binary fast radial symmetry (ICBFRS) detector and pseudo-zernike moments based support vector machine (PZM-SVM) classifier is proposed. In the detection stage, the scene image containing the traffic signs will be converted into Lab color space for color segmentation. Then the ICBFRS detector can efficiently capture the position and scale of sign candidates within the scene by detecting the centers of circles. In the classification stage, once the candidates are cropped out of the image, pseudo-zernike moments are adopted to represent the features of extracted pictogram, which are then fed into a support vector machine to classify different traffic signs. Experimental results under different lighting conditions indicate that the proposed method has robust detection effect and high classification accuracy.