How ANPR Camera Systems Work, Step-by-Step

Automatic Number Plate Recognition (ANPR) technology is a common sight in car parks, traffic intersections, and toll booths all over the world. It uses Optical Character Recognition (OCR) to automatically read and interpret the characters on vehicle licence plates, and then uses this data to help with managing traffic and improving security.

ANPR technology has been around since the mid-1970s, but it didn't really take off until the early to mid-2000s. This was when advancements in computer vision and image processing made ANPR systems much more accurate and affordable to use. The technology behind it keeps evolving, which is why it becomes more and more popular with each passing year.

If you've been looking to step up your car park's security, installing ANPR cameras is one of your best options. ANPR allows you to enforce parking rules, deter crime, and even boost your income – all without the need for personnel on the ground. But how do these systems actually work? And how do you go about setting up an ANPR system of your own?

Well, that’s what we’re here to explain today. Read on to discover the step-by-step process of how ANPR cameras work, from capturing images to putting the data they collect to good use!

1. Capturing the License Plate

ANPR systems are made up of a complex network of high-resolution cameras and processing equipment. These cameras are strategically placed to get a clear view of licence plates, and are usually equipped with infrared sensors so they can work in low (or even no) visibility.

The process begins when one of these cameras spots a passing or parked vehicle and takes a photo of its relevant details. This image is then saved to the system's database for further handling.

2. Preprocessing the Image

After the image is saved, the system performs preprocessing to enhance the quality and extract the licence plate region. This involves tweaking the brightness, contrast, and orientation to make sure the licence plate is easily identifiable, reducing the chances of identification errors.

3. Segmenting and Translating the Characters

Once the system has successfully extracted the licence plate, it separates the individual characters and digits from the plate. This leads onto the core of the system: Optical Character Recognition (OCR). OCR takes the segmented characters and converts them into readable text, which is then logged for the next step.

To improve accuracy, the system may check to see if the recognised plate number is valid. This involves looking at things like the plate format, character spacing, and other specific rules based on the region's licence plate standards.

4. Querying the Database

Some (but not all) ANPR systems are connected to databases containing information about registered vehicles. After successfully recognising a licence plate, the system may query the database to retrieve information such as the vehicle owner's details or registration status. In a car park, for example, the system can check if the owner has paid for their ticket or overrun their time slot.

5. Taking Action

Depending on the system's setup and intended use, a variety of actions can be triggered upon recognising a licence plate. This can range from sending alerts to law enforcement for stolen vehicles, allowing authorised vehicles to pass by opening gates, to simply keeping a record of entry and exit times in parking areas.

6. Storing the Data for Future Use

Once the relevant action has taken place, ANPR systems typically store the captured images, licence plate numbers, and associated data for future reference or law enforcement purposes.

Talk to the UK’s Leading ANPR Specialists

Now that you've got a good idea of how ANPR cameras work, you might be leaning towards having a system set up in your own car park. If so, you've come to the right place!

At Britannia Parking, we have over 25 years of experience installing high-level ANPR systems in car parks all over the UK. Thanks to the countless projects we’ve worked on in the past, we're well-equipped to design a cost-effective, fully optimised ANPR solution that can boost your revenue and safety, all while keeping the installation process as smooth as possible. No matter your car park's size or layout, you can trust our team to deliver the perfect system to meet your needs.

Ready to get started? Book a consultation and take the first step toward streamlining your parking management today!