LPR matcher

The LPR matcher is the AutoVu™ software engine that matches license plates captured by Sharp cameras to license plates in a data source such as a hotlist or permit list, or to previously captured license plates, such as for overtime enforcement. The LPR matcher determines if a plate read results in a hit.

How LPR matcher logic works

Real-world conditions make license plate recognition difficult. License plates might have characters that are hidden by dirt or snow, while other characters’ paint may be faded or chipped. Some license plates have pictures or screws that can be misread as legitimate license plate characters.

If the LPR matcher were only capable of raising a hit based on an exact match, many plates that should be hits would instead be missed.

Example

A hotlist contains the plate ABC123. While on a patrol, a Sharp camera reads the license plate ABC12, but is unable to read the last character because the character’s paint is chipped.

The LPR matcher must be capable of more than “yes/no” logic because the plate read ABC12 might be a match. It would be better to raise the hotlist hit, and let the Genetec Patroller™ operator decide whether or not the hit is legitimate. To do this, the LPR matcher uses different levels of “maybe” logic to allow for more possibilities for a plate match.