Based On Digital Image Processing Technology, Automatic License Plate Detection And Segmentation Algorithm,

With the fantastic spur in economy and rapid development of the owning amount of automobile, the highway communication becomes one of the most important communication and transportation ways in our country. And now it is infrastructures that the country developed energetically. Also crowded urban traffic needs more advanced and more effective traffic administration and control system. Intelligent Transportation Systems (ITS) which makes use of electronic information technology to raise management efficiency, traffic efficiency and traffic security becomes main direction of traffic administration.License Plate Recognition (LPR) is one of the critical techniques for the intelligent transportation system. The system can automatically register, verify, monitor vehicle or report to the police with automatic recognition for vehicle license plates. So it can be used in many kinds of occasions, such as the charges system of expressway, monitoring system at road and roll-gate, charge and monitoring system at the district, parking area, guide system, the system counting the quantity of vehicle passing in a certain period time, et.Based on digital image procession technology, computer vision technology and artificial neural network technology, the paper deeply researches and analyses an automobile license plate identification system. And I have finished following works in this article:(1) Detection of vehicle license plate. Two license plate location methods are put forward in this article, which can locate license plate exactly from the license plate images. The first one is license plate location based on top-hat transform and wavelet transform, and the other one is license plate detection based on projection and mathematical morphology.(2) Character segmentation. Two character segmentation approaches are discussed in this article, which can segment characters from license plate effectively. The first one is character segmentation approach of license plate based on Laplacian Transformation, region growing and prior knowledge, and the other one is character segmentation method of license plate based on quick region marking method and the large-interval-based character locating algorithm.(3) The software platform of License Plate Recognition. A software system coded by c/c++ languages is designed and accomplished, it integrates all of our algorithms, it provides convenient way to observe the algorithm results.All of our algorithms have been proved in the software platform. Experiments have been conducted on a large number of typical car images taken from various scenes and different conditions, the result shows that the rates of the two license plate location methods achieve 98.89% and 97.78%, respectively, and the rates of the two character segmentation approaches can achieve 97.2% and 98.44%, respectively.