Research On Technology Of Automatic License Plate Recognition

The domestic expressway, urban road and parking area, etc are constructed gradually, with the high-speed development of our national economy. The requisitions on the traffic control and safety management are improved day by day. The Intelligent Traffic System (ITS) has already become the main direction of present traffic administration development, and vehicle License Plate Recognition (LPR) as core of ITS, play a very important role. It occupies important role in the project management of expressway, urban road and parking area, etc. Its wide application will contribute to the process of the traffic management automation of our country.The paper is based on image preprocessing technology,license plate location technology,character segmentation technology and BP neural network technology to solve the LPR problem. First, through gray equalization,median filter and so on, the noise will be reduced well and the lengthways-texture area can be strengthened; through deeply study in license plate character and license plate location, a license plate location algorithm based on character texture characteristics and vertical projection is put forward that can search the license plate area accurately; based on transcendent information of license plate and regional growing algorithm and Canny transformation, This method realizes license character segmentation; last, the paper analyzes the structure of the neural network with relevant theories and emphatically discusses the theory principle of the neural network and the application method in character recognition with it. BP Neural network is used as a method to recognition the single character at end of this paper.