A Study On Techniques Of Car License Plate Recognition Based On Neural Network

License plate recognition (LPR) system is the main part of the contemporary Intelligent Transportation System (ITS), and it can be applied in vehicle management situations of all levels and all kinds. Compared with traditional vehicles managing methods, it improves managing efficiency and level, and saves manpower and material resources, realizes scientific standard management and ensures traffic order. Therefore, it has comprehensive application prospect.LPR System consists of three modules in general, those are: license plate locating, character segmentation and character recognition. Based on image procession technology, computer vision technology and artificial neural network technology, the paper deeply researches and analyses an automobile license plate identification system. Chapter 1 gives a full introduction of the present situation of technologies in automatic number-plate recognition all around the world. It analyzes that the development tendency of technologies of automatic number-plate recognition on the basis of discussing the specialization of automatic number-plate recognition in our country. In chapter 2, there are some brief introduces of commonly used digital image processing. Chapter 3 briefly introduces the commonly used car license plate locating technology, and adopts a car license plate locating algorithm based on the counted of the edge. Chapter 4 discusses some basic principles of image segmentation, and segments characters of license plate by vertical projection information and the prior knowledge. Chapter 5 introduces some characteristic extracting methods of character recognition, 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. Lastly neural network is used as a method to recognition the single character.As the test result, it proves that this recognition system can relatively accurate to locate license plate and recognize characters and system's performance is good. It shows that combined pretreatments and recognition techniques can improve the ability of recognition, and the combination of neural network and artificial intelligence under the principle of efficiency and practicality will be two major development tendencies of pattern recognition.