Method of license plate location based on edge detection and color information

A new method of license plate location is designed in the paper and it is divided into two steps, which are rough location step based on gray image processing and precise location step based on color image processing. Firstly, the color car image is converted to the gray one from which horizontal and vertical edge images are extracted using Haar wavelet and Gabor filter. The rough location is achieved based on the specific projection features of these edge images. Then the color plate image roughly located by the first step is converted to HSI space. The binary image is obtained through the threshold segmentation method according to the color information of license plate. The plate's precise position parameters are determined through making projection analysis of the binary image. The simulation result shows that the location method in this paper is efficient and effective.