How Does Licence Plate Recognition Work?

3 min read

Providing truly frictionless parking experiences for your customers starts with investing in innovative technologies that minimize physical touchpoints. Licence plate recognition technology continues to play a vital role in allowing parking operators and facility managers to do just that.

Licence plate recognition is not as difficult to understand as it may seem. Simply put, the technology enables vehicle licence plates to act as a credential at access points, simplifying the payment process and allowing customers to enter and exit your facility easily.

But how does licence plate recognition work for parking access and control? Below are the back-end processes that occur from when a vehicle licence plate is recognized to when it exits the facility and every moment in between.

Step 1: Capture

A video or still image of a vehicle is captured using either an optical or an infrared camera. System programmers train the machine learning algorithms to recognize vehicles and distinguish between multiple vehicles within the frame to ensure all licence plates are captured.

Step 2: Localization

Once the vehicle licence plate is captured, a licence plate localization algorithm is used to determine the specific area of interest in the camera’s field of view where the licence plate is located. Artificial intelligence (AI) is used to differentiate the physical properties of a licence plate from other text on the vehicle.

Step 3: Character Recognition

Character recognition algorithms are used to determine the alphanumeric characters inside the localized part of the image that was previously captured. This is done by comparing each character image to representative images stored in the database.

Step 4: Post Processing

The licence plate is then compared to either access, notification or block lists to potentially vend the gate or notify via text or email about the licence plate passage. Unclear licence plate matching can be enabled to allow exceptions of misreads of some characters. If multiple cameras are used (front/back, IR/colour), reads from the different cameras can be compared to select the read with the highest confidence.

Licence plate recognition technology is an intelligent system that can read, understand and approve licence plates quickly and efficiently. Investing in smart technologies such as licence plate recognition provides facility managers with a foundation to build truly frictionless experiences for their visitors.

References

Donatucci, A. (2021, May 10). Enforcement Technology: Automatic License Plate Recognition. ParkingIndustry. Retrieved June 20, 2022, from https://www.parkingindustry.ca/feature-articles/enforcement-technology-automatic-license-plate-recognition?rq=license+plate.

Lato, L. (2021, May 10). Automatic license plate recognition: A high-level technical overview. ParkingIndustry. Retrieved June 20, 2022, from https://www.parkingindustry.ca/parking-technology/automatic-license-plate-recognition-a-high-level-technical-overview?rq=license.

Sharma, A. (2021, May 10). License Plate Recognition vs. License Plate Association. ParkingIndustry. Retrieved June 20, 2022, from https://www.parkingindustry.ca/parking-technology/license-plate-recognition-vs-license-plate-association?rq=license+plate+recognition.