Troubleshooting: Low ALPR read rates or poor quality ALPR reads displayed - SharpZ3 | SharpOS 13.4

AutoVu™ SharpZ3 Administrator Guide 13.4

Applies to
SharpZ3 | SharpOS 13.4
Last updated
2023-01-24
Content type
Guides > Administrator guides
Language
English
Product
SharpOS
SharpZ3
Version
13.4

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 SharpZ3 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 SharpZ3 camera to ignore approaching license plates until the characters are larger. For example, when the minimum character height is set to 15 pixels, a SharpZ3 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 SharpZ3 and determine the acceptable minimum character height. To increase the minimum character height, see Filtering plates based on character height for SharpZ3 cameras.