The Research Of Vehicle Plate Recognition Technical Based On BP Neural Network

Vehicle plate recognition technology is the key technology of the public security of law enforcement system, highway automatic charge system, city road supervisory system and the intelligent parking lot management system. Vehicle plate recognition technology can be used in the fields such as road charge and traffic. It's application will be helpful to save manpower cost, raises efficiency and improvement to manage system. Along with the quick increase of the automobile quantity of our country, vehicle plate recognition technology presents huge economic value and realistic meaning.This paper has studied a lot of method and theory about vehicle plate location, character divide and character recognition systemically. In the aspect of vehicle plate location , author adopt the algorithm of the frequency of gray scale alternate to seek approximately location. Use the characteristic of rich vehicle plate regional veins to find out every possibility vehicle plate area. Then for these candidate regional gray scales that make vertical direction projection. According to this, differentiate really fake vehicle plate. Eventually, get only vehicle plate area. After correct position approximately, according to HSI color space theory, get accurate vehicle plate area.About character divide, author uses 2 value image vertical projection methods with known plate knowledge to divide character apart. So can eliminate vehicle plate around two end positional accuracies the influence for that character divides into shelf. In the aspect of character recognition, this paper has used Chinese character, English character and digital & English 3 neural networks to carry out character recognition. Experiment result shows that this recognition algorithm has gotten better recognition effect.