Identification process
Automatic license plate recognition is a pattern recognition technology that uses dynamic video or static image of vehicle to automatically recognize license plate number and license plate color. The hardware base generally includes a trigger device (monitoring whether the vehicle enters the view position), a camera device, a lighting device, an image acquisition device, a processor (such as a computer) that recognizes the license plate number, and the software core includes a license plate location algorithm, a license plate character segmentation algorithm and optical character recognition algorithms, etc. Some license plate recognition systems also have a function of judging if there is a car through a video image, which is called video vehicle detection.
A complete license plate recognition system should include vehicle detection, image acquisition and license plate recognition. The image acquisition unit is triggered when the vehicle detection portion detects that the vehicle arrives and the current video image is acquired. The license plate recognition unit processes the image, locates the license plate position, divides the characters in the license plate for identification, and then forms a license plate number for output.
Vehicle detection
Vehicle detection can use buried coil detection, infrared detection, radar detection technology, video detection and other methods. Among them, the ground coil detection is the most accurate and stable.
License Plate Number identification
In order to carry out license plate recognition, the following basic steps are required:
1. License plate positioning to locate the license plate in the picture;
2. The license plate character is divided and the characters in the license plate are separated.
3. License plate character recognition, identifying the divided characters and finally forming the license plate number.
In the license plate recognition process, the license plate color is identified according to different algorithms, which may be implemented in the above different steps, usually in cooperation with the license plate recognition and mutual verification.
