| The technology of License Plate Recognition is the main part of Intelligent Transportation System. It will accelerate the progress of ITS. In this thesis, the key technology of LPR was put into researching. And an effective method was brought forward. The programs of the system were completed and put into experiment. And it includes the main points as follow. Firstly, how to select a lamp-house for the system of lamp-house compensation was discussed. Secondly, a method of poly-hierarchy accumulating projection was put forward to locate the license plate. The method reduces the image area through three steps, which are coarse segmentation, the second segmentation and fine segmentation. Then The characters were segmented by using the method of improved projecting, under the condition of that the image of characters had been enhanced. Thirdly, a poly-hierarchy sort method was designed to improve how to recognize the Chinese characters, which includes three parts: template matching coarse sort part, coarse sort part of character frame stroke number and fine sort part. Finally, the other characters were put into the recognizing block to recognize according to its position in the license plate. There are three blocks that are letter block, number block and letter-number block. All these blocks are composed by three classes: template matching part, coarse mistiness recognition and fine mistiness recognition. The experimental results showed that this system can distinguish all the characters with preferable recognition rate and exactness. |
