How you configure the ALPR matcher depends on your enforcement scenario. In some AutoVu™ systems, you’ll want an exact match only. In other systems, you'll benefit from having a false positive on a potential match because it decreases the chances of missing a vehicle of interest.
Use the following best practices when configuring ALPR matcher settings:
- Exact match
- The ALPR matcher always looks for an exact match if possible, but you can configure it to allow only exact matches. This is typically used when you have very large hotlists (millions of entries). By limiting the number of possible matches, you lighten the processing load on the Genetec Patroller™ computer, and you decrease the number of false positives that you would normally get from a list of that size.
- To allow only exact matches, turn on the Simplematcher feature in Genetec Patroller™ Config Tool, and turn off OCR equivalence.
- OCR equivalence
- By default, the ALPR matcher allows for one OCR equivalent character. You can allow as many as you want, but generally you should not allow more than two because you’ll get too many false positives.
- Number of differences allowed
- By default, the ALPR matcher does not allow any number of differences. The number you allow depends on the plates in your region. The more characters on a plate, the more differences you can allow, but generally you should not allow more than two because you’ll get too many false positives.
- Common and contiguous characters
- (Used for overtime enforcement only) By default, the ALPR matcher looks for five common, and four contiguous characters to generate an overtime hit. The number you specify depends on the plates in your region. The more characters on a plate, the more common and contiguous characters you can allow.