License Plate Recognition Key Technologies

The research and development of license plate recognition system are hot topics in moden traffic development and determine the intelligentization and modernization of traffic system. The paper has gone deep into very step of LPR relatively,the main research work of this thesis is presented as follows:1. analsing the cardinal principle and shortcoming of commonly licence plat location method .this paper base on the mathematical morph- ology location License plate, then according to the ratio of License' lengh and wide, eliminate fake License plate . The experimental result show that this method able to extract license plate field quickly and efficiently.2. At frist sum up common algorithm of characters egmentation, This paper used inclinerevising and rimcleaning method to eliminate the disturbed factors mostly. The Singling character is picked out by projection method comcombining with the transcendent information.3. analsing and sum up commonly method of features exteaction ,This paper pick up features that make use of K-L transform, K-L transform can decrease feature vector dimension and keep to the letter image main features,this method decrease recognition difficlt.4. Character recognition: analsing and summing up the commonly method of character recognition. This paper make use of BP network recognition character, there are four BP networks ,the frist BP network recognition Chinese character, the second BP network recognition alphabet character,the thrid BP network recognition alphabet and digtal character, the fourth BP network recognition digtal character. This method has highter rate and relatively faster.