The Research Of License Plate Recognition

Vehicle plate recognition technology is the key technology of highway automatic charge system, city road supervisory system, the public security of law enforcement system and the intelligent parking management system. Vehicle plate recognition technology can be used in the fields such as road charge and traffic, the 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.We did a lot of research on image processing, vehicle plate location, character divide and character recognition systematically. Then we proposed some effective strategies and did some experiments. Based on these, we completed a LPR software system on matlab6.5.In the aspect of vehicle plate location, we adopted a method through edge detection and the characteristic of rich vehicle plate regional veins to find out some candidate of vehicle plate area. Then according to HSI color space theory got accurate vehicle plate area.About character segmentation, we used 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 isolated.In the aspect of character recognition, we normalized character by neighboring insertion value. We used Chinese character, English character, digital & English character and digital character BP neural networks to train the sixteen dimension wavelet characteristics.