What is the general principle for license plate recognition ?

ANPR/ALPR recognition process

The Optical Character Recognition (OCR) technology has been at the core of NESTOR TECHNOLOGIES‘s business since its establishment in 2001. So, this technology has evolved over the years, now utilizing powerful algorithms based on Artificial Intelligence. The automatic license / number plate recognition is now boosted !

But what is the general principle for recognizing the characters on a vehicle’s license plate within an image?

In the diagram above, we outline the process that breaks down into 5 major steps :

Acquisition of the vehicle image by a high-performance digital camera.

Detection of the license plate’s position in the image.

Extraction and recognition of the characters contained within the plate.

Classification of the country and the State of origin of the license plate.

Export of results to a screen, a file (JSON, XML…), a SQL database, or make them available via a Web service…

Automatic Recognition of license / number plate characters is performed by our ANPR / ALPR engine via our TREX Software Suite.