The Research On License Plate Location And Character Identification In The Automatic Police System

With the high speed development of the modern traffic, intelligent transportation system has become the main development trend of the current traffic management system. As a part of the intelligent transportation system, the automatic police system is important to the city traffic system. It decreases the management cost of urban traffic, saves plenty of financial resources and material resources. License plate recognition technology is a key technology of the automatic police system, so the study of license plate recognition technology is important practical significance.There is more research on the location and character identification of the license plate in the recognition techology.At the location of the liecese plate stage, a series of image processing technology has been done in the vehicle images that we received: grey, image enhancement , binary image ,median filter, edge detection; analysis of the character of the common license plate. Based on the results of image processing and the feature of the license plate, we make the horizontal projection and vertical projection of the license plate to gain the area of the license plate after the pretreatment of the collected image of the car.Recognizing character of the image area of license plate has three steps: the correction of the license plate, the division of the character, and the identification of the character. We correct the license plate by the methods based on matrix. We divide the character of the license plate by the horizontal project. The identification of the character has two steps: the character's classification, the different identification methods of the different kinds. We analysis the rationality of the methods we used.