Vehicle registration plate
A vehicle registration plate, also known as a number plate or license plate or licence plate, is a metal or plastic plate attached to a motor vehicle or trailer for official identification purposes. All countries require registration plates for road vehicles such as cars, trucks, and motorcycles. Whether they are required for other vehicles, such as bicycles, boats, or tractors, may vary by jurisdiction. The registration identifier is a numeric or alphanumeric ID that uniquely identifies the vehicle or vehicle owner within the issuing region's vehicle register. In some countries, the identifier is unique within the entire country, while in others it is unique within a state or province. Whether the identifier is associated with a vehicle or a person also varies by issuing agency. There are also electronic license plates.
Some jurisdictions license non-traditional vehicles, such as golf carts, particularly on-road vehicles, such as this one in Put-in-Bay, Ohio.
Two Swedish snowmobiles with license plates attached to the side of the vehicles
The damage to the enamel on this Wyoming license plate from 1916 exposed the iron, causing it to rust.
In 1944, Wyoming license plates were made of soybean-based fiberboard due to metal conservation for World War II.
Automatic number-plate recognition
Automatic number-plate recognition is a technology that uses optical character recognition on images to read vehicle registration plates to create vehicle location data. It can use existing closed-circuit television, road-rule enforcement cameras, or cameras specifically designed for the task. ANPR is used by police forces around the world for law enforcement purposes, including checking if a vehicle is registered or licensed. It is also used for electronic toll collection on pay-per-use roads and as a method of cataloguing the movements of traffic, for example by highways agencies.
The system must be able to deal with different styles of vehicle registration plates.
License plate recognition process
A Merseyside Police car equipped with mobile ANPR
Systems must be able to recognize international license plates as such.