Abstract: The location of license plate plays a crucial role in license plate recognition system. Based on the rich edge information and unique features of the license plate region,a practical and effective method of locating the plate was proposed. Firstly, the original image was transferred to HSI space, and the rough locations were detected by using the edge information of the characters and the operation of the mathematical morphology; and then, the accurate region of license plate was decided by the SOM using four features proposed by this paper. Finally, the experiments on 80 color images show that the efficiency of the proposed algorithm is 96. 25%.

Key words: License plate location, HSI space, Morphology, Self organizing map