Troubleshooting: Low ALPR read rates or poor quality ALPR reads displayed - SharpV | SharpOS 14.2

AutoVu™ SharpV Deployment Guide 14.2

Product
SharpOS
SharpV
Content type
Guides > User guides
Version
14.2
Language
English
Last updated
2023-03-14

If you are experiencing poor read rates when detecting license plates, you can resolve it by modifying the minimum character height.

Cause

Character height is a setting in the Sharp Portal that determines the acceptable pixel height for the characters within a license plate. By default, the minimum character height is set to 15 pixels to capture license plate reads that are farther away. However, this might lead to poor ALPR performance and might not be useful in many SharpV installations. This is particularly true in fixed or in mobile parking applications where the accuracy of the plate read is more important than the detection of distant license plates. You should configure the SharpV camera to ignore approaching license plates until the characters are larger. For example, when the minimum character height is set to 15 pixels, a SharpV camera might capture license plates of cars that are parked far away and do not need to be monitored.
IMPORTANT: The character height filter, plate tilt filter, and the region of interest work in conjunction to filter plate reads. Consider their combined affect when configuring and troubleshooting the system.

Solution

Monitor the camera feed for the required SharpV and determine the acceptable minimum character height. To increase the minimum character height, see Filtering plates based on character height for SharpV cameras.