Color and Texture Analysis Based Vehicle License Plate Location
基于颜色和纹理分析的车牌定位方法

This paper presents an effective license plate location algorithm, which employs color and texture analysis to extract the number plate from the complicated background image. Based on the HSV color model, the algorithm calculates the distance and the similarity in the color space to segment the color image. Only those parts of the input image that fulfill a set of license plate properties need to be considered for a more thorough inspection. To the segmented image, the texture and structural features are analyzed to locate the license plate correctly. The algorithm has been tested with 60 color image obtained from tollgete, crossroad and parking lot, etc. More than 95% image can be proceesed correctly, whereas other images are disturbed by the complex backgrounds of the images. It is shown that, different from most license plate location methods, the algorithm has fewer limits to the car size, the car position in the image and the image background. Meanwhile, with the fast focusing technique, the view angle of the video camera can cover a wider area while the processing time can still be fast. So, the algorithm can be employed to the applied vehicle license plate recognition system.