Automatic number plate recognition (ANPR) is a group supervision method that uses optical character detection on images to examine the license plates on a vehicle. Licence plate recognition can be used to store the images that have been captured by the camera and the text of the number plate. Some of the systems can even store the photographic image of the driver of the vehicle. This technology is used in safety and traffic application worldwide.

License plate recognition technology or ANPR has gained popularity in security and traffic applications as it is based on the fact that all vehicles have a license plate and there is no need to install any additional tracking apparatus. The main advantage is that the system stores the image record for future references.

The system uses lighting (such as Infra-red) and a camera to take the image of the front or rear of the vehicle which is then analyzed by image-processing software, which extracts the image and the plate information. This data is then used for enforcement or record collection and maintenance.

License plate recognition system or Automatic number plate recognition systems have the following components:

1. License plate capture camera ? which captures the images

2. Lighting mostly infra-red, which the driver cannot recognize

3. Framework that is a connection between the image capturing unit and the computer and the software

4. A computer or PC which runs the system

5. The software that is used by the system.

6. The proceedings are recorded on a database which includes the images of the license plate and the driver face if that option is present in the system.

7. The system also uses other hardware including an automatic license plate reader.

Car Detector has two different models or variations:

1. Fixed Camera LPR systems: CarDetector records and informs the concerned authorities regarding any unauthorized vehicles that travel through the chosen security zone, even if the vehicle is moving. The system records the time of detection, the plate number and image and the entire car image if required.

2. Mobile LPR Systems (CDMS): This is designed for mobile law enforcement vehicles. The system automatically detects the vehicle and extracts the plate image, which is then analyzed and matched with the existing database. This helps the police in detecting stolen or suspect vehicles.