ANPR

Automatic number plate recognition (ANPR) is a technology that uses cameras and optical character recognition to automatically read vehicle license plates. Images of moving or stationary vehicles are captured, plate regions detected, characters segmented, and the alphanumeric sequence is recognized and stored as data. ANPR systems are used for identifying vehicles of interest and for tracking movement across monitored areas.

Typical ANPR setups include cameras, illumination (visible light or infrared), processing units, and integration with databases. The workflow generally involves image capture, plate localisation, character recognition, and cross-checking against watchlists or databases. Some systems operate in near real time, generating alerts, while others archive records for later analysis.

ANPR can be deployed at fixed locations such as roadways, toll booths, or border crossings, as well as on mobile platforms including patrol vehicles and drones. Modern systems may combine multiple camera angles and sensors to improve recognition under varying conditions.

Common applications include automated traffic enforcement, toll collection, parking management, border control, and investigation support. In smart city programs, ANPR data may be used to monitor traffic patterns and optimize urban planning.

Recognition accuracy can be affected by plate design, fonts, dirt or obstructions, weather, lighting, motion blur, and the viewing angle. Some jurisdictions require clear signage or legal basis to use ANPR data, and concerns about privacy and data security are regularly addressed through governance frameworks.

Because ANPR involves the collection and retention of personal data linked to individuals, many countries impose data protection requirements, access controls, retention limits, and oversight. Operators often publish policies and establish auditing procedures to ensure lawful use.

Advances include multi-frame analysis, improved OCR for diverse plate styles, and integration with broader intelligent transport systems. Ethical and legal considerations continue to shape deployment and governance.