Abbreviated as ANPR and also known as licence plate detection systems, automated number plate recognition systems use computer vision and optical character recognition technologies to read the registration numbers on number plates of vehicles to identify them and build data in terms of their location, passes, entries and exits. The police and toll plaza admins use these systems for their specific purposes like traffic enforcement and toll collection.
Acronyms of ANPR
Automatic number plate recognition is known as several other terms. Some common terms are as follows:
- ALPR (Automatic licence-plate recognition)
- ALPR (Automatic licence-plate reader)
- AVI (Automatic vehicle identification)
- ANPG (Automatisk nummerpladegenkendelse)
- CPR (Car-plate recognition)
- LPR (Licence-plate recognition)
- LAPI (Lecture automatique de plaques d’immatriculation)
- MLPR (Mobile licence-plate reader)
- VLPR (Vehicle licence-plate recognition)
- VRI (Vehicle recognition identification)
The Police Scientific Development Branch invented ANPR in 1976 in Britain. By 1979, prototype systems were used to recognise vehicle number plates and delivery of contracts to make industrial systems. At first, EMI Electronics came into existence. In later years of the early 1980s, CRS or computer recognition systems came into the light. In the early trials, the CRS were installed at the Dartford Tunnel and A1 road.
The first detection and arrest of a stolen car happened in 1981. During the 1990s, ANPR systems were not in extensive usage and development of respective software to make the systems easily available at reasonable cost. In the early 2000s, the use of ANPR data was documented. It was the year 2005 when a urder case was solved in Bradford in the UK by using the automatic number plate recognition system.
ANPR systems have numerous components to make them operational and function well. The system runs on standard home computer hardware after its integration with databases or other applications. At first, it utilises an array of image manipulation techniques to detect, identify, and normalise and improve the number plate image. After that, it uses OCR or optical character recognition technique for the extraction of the licence plate alphanumerics.
As a user, you can deploy this system in two ways. In the first one, you can use it to detect vehicles in real-time at the lane location. In the second way, you can use it to work for all lanes for image capturing and transmission. All the information can easily be sent to the control room and allied authoritative personnel.
The automated number plate recognition systems highly utilise OCR (optical character recognition) images clicked by cameras. With several technical advancements, the systems can easily read characters printed in any font, style, and size on number plates of stable or moving vehicles.
In today’s world, ANPR software needs seven primary algorithms for the identification of licence/number plates of vehicles. The algorithms are as follows:
- Plate localisation
- Plate orientation and sizing
- Character segmentation
- Optical character recognition
- Geometrical/syntactical analysis
- Averaging of the recognised values
Some popular use cases or application areas of ANPR systems are as follows:
- Automatic parking management (Smart Parking)
- Automated collection of tolls and toll booth records
- Effective traffic law enforcement
- Journey time analysis
- Security monitoring and border crossings
- Traffic management and traffic optimization
- To assist visitor management systems in recognizing guest vehicles
- Vehicle theft prevention
ANPR systems are highly useful. Having an idea about the basics of automatic number plate recognition systems can help you use the same well and get the desired results in improving security and safety.