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.