License plate recognition technology requires that the moving license plate can be extracted and recognized from complex background. Through license plate extraction, image preprocessing, feature extraction, license plate character recognition and other technologies, vehicle license plate, color and other information can be recognized. At present, the latest technology level is the recognition rate of letters and numbers can be achieved.99.7%The recognition rate of Chinese characters is achievable.99%。 In parking lot management, license plate recognition technology is also the main means to identify vehicles. In "Technical Requirements for Vehicle Image and License Plate Information Acquisition and Transmission System of Parking Yard" constructed in Shenzhen, license plate recognition technology has become the main means of vehicle identification. License Plate Recognition Technology Combined with Electronic Non-stop Toll Collection System（ETC) Recognition of vehicles, passing vehicles through the intersection without parking, that is, to achieve automatic identification of vehicles, automatic charging. In the management of parking lot, in order to improve the efficiency of entry-exit vehicles, license plate recognition is aimed at vehicles without parking fees (such as monthly trucks, free internal vehicles), building unattended fast lanes, free of cards and non-stop access experience, which is changing the management mode of entry-exit parking lot.
License Plate Recognition System(Vehicle License Plate Recognition，VLPR) It refers to the technology that can detect the vehicles on the monitored road surface and automatically extract the license plate information (including Chinese characters, English letters, Arabic numerals and license plate color) for processing. License plate recognition is one of the important components of modern intelligent transportation system, and it is widely used. Based on digital image processing, pattern recognition, computer vision and other technologies, it analyses the vehicle image or video sequence captured by the camera, and obtains the unique license plate number of each vehicle, thus completing the recognition process. Through some follow-up processing means, the functions of parking fee management, traffic flow control index measurement, vehicle positioning, car anti-theft, highway overspeed automation supervision, highway toll station and so on can be realized. It has practical significance for maintaining traffic safety and urban public order, preventing traffic jams and realizing automatic traffic management.
Vehicle license plate number is the only vehicle"Identity" identification and automatic license plate recognition technology can automatically register and verify the "identity" of a vehicle without any change. This technology has been applied to various fields such as road toll collection, parking management, weighing system, traffic guidance, traffic law enforcement, road inspection, vehicle dispatching, vehicle detection, etc. All right.