The optimal matcher settings for AutoVu™ Free-Flow parking enforcement using Pay-by-Plate Sync can be different than those used for law enforcement. By modifying a config file, you can configure specific fuzzy matching rules for parking enforcement.
Before you begin
- Test your system with the default matcher settings. If the read accuracy rate meets your requirements, then do not adjust the matcher settings.
- Depending on the font design, some plate characters can look very similar to other characters. These are called "OCR equivalent characters". To modify which characters the system considers equivalent (for example, 2 and Z), you can edit the MatcherSettings.xml general matcher file at C:\Program Files\Genetec Security Center X.X.. For more information, see LPR matcher technique: OCR equivalence.
What you should know
- Environmental factors such as dirt or snow can partially obstruct license plate characters and increase the likelihood of partial plate reads. In addition, similarly shaped letters and numbers, like “2” and “Z” or, “8”, “B”, and “0”, can reduce plate read accuracy. Using fuzzy matching, AutoVu™ can compare reads not only to exact matches in permits, but also to potential or probable matches.
- Matcher settings for AutoVu™ Free-Flow systems that use the Pay-by-Plate Sync plugin are configured using the Genetec.Plugins.MobilePBP.dll.config file. The <FuzzyMatcherSettings> section of this file is similar to the MatcherSettings.xml file, which is used to configure matcher settings for the rest of the AutoVu™ system.
- For more information on how matcher settings work in an AutoVu™ system, see MatcherSettings.xml file.
On the workstation where the plugin is installed, open Windows Explorer,
navigate to C:\Program Files (x86)\Security Center
Plugins\MobilePBP, and open
Genetec.Plugins.MobilePBP.dll.config in a text
- There are 12 PerLengthSetting lines, each containing NumberOfDifferencesAllowed and NumberOCREquiAllowed tags.
- Each PerLengthSetting line corresponds to a plate character length. The line you edit depends on the number of characters on the license plates in your patrol region.
- Ignore the first line because it represents plates with zero characters. The second line represents plates with one character, the third line represents plates with two characters, and so on for a maximum of 11 possible plate characters.
- You can edit more than one line to apply settings to plates of different character lengths.
Identify the lines that match the number of characters on the license plates of
For example, license plates in Canada generally include six or seven characters. Therefore, you would modify the PlateWith5Characters and PlateWith6Characters lines.
Modify the configurations for each plate length as required.
In the following example, for license plates with 6 characters (PlateWith5Characters), two differences and two OCR equivalent characters are allowed.<PerLengthSetting name="PlateWith5Characters" NumberOfDifferencesAllowed="2" NumberOfOcrEquivalentsAllowed="2" />
- Number of differences allowed
- This is the number of character differences that are allowed between the license plate read and the license plate in the permit list. 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.
- Number of OCR equivalence allowed
- Similar-looking Latin-based characters (such as "2" and the "Z") can sometimes be mistaken by Optical character recognition (OCR) systems. 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.
- Save the file and close the text editor.
To restart the Pay-by-Plate
Sync plugin role,
deactivate the plugin and then reactivate it.