Research On License Plate Recognition Based On Image Processing Technologies

Study on the license plate recognition system is an important part of intelligent traffic system. It can identify the license plate number through the vehicles photo shot by the camera. The computer can identify the plate number automatically without influencing the vehicles'state, so it can reduce the complexity of the work of the traffic management.Study on the license plate recognition system has played an active role in many traffic related questions, such as charging automatically in tollgates without stopping, the measurement of traffic flux control target; automatic recognition; automatic accident report in expressways, checking without stopping, location; guard againt theft; check and track vehicles'irregular and illegal behaviors; maintain traffic safety and social stability; avoid traffic jam; speed service in tollgates, ease the traffic intensity.This article, firstly, introduces the background knowledge and meaning of carrying out the subject of the license plate recognition system, expounds the general situation of its development at home and abroad, and difficult point of the license plate recognition.Secondly, this article expounds the main technologies of the license plate location, character segmentation and recognition respectively, introduces the ordinary methods for the license plate location. This article, firstly, applys for the methods of based-on projection to locate license plate; then, puts forward the methods of based-on improvement of vertical projection to be applied for characters segmentation; finally, applys for the methods of based-on digital character outline's feature to layout digital classifier and digital and alphabeti classifier. This article carrys on simulation experiment which utilize those methods that are refered to preceding part of the next.Lastly, it concludes the deficiency of the license plate recognition system, brings out suggestion to improve this technology, and points out prospect and assumption of this article.