Using the character height filter, you can configure the SharpV to only detect license plates within a certain distance from the camera.
What you should know
- By default, the camera detects license plates that are close (100 pixels) or far away (17 pixels). In an installation such as an access control gate where plate read accuracy is more important than the detection of distant license plates, you can restrict the filter range to detect the license plate only when the vehicle is near the gate.
- If the SharpV is installed at a low angle and license plates have a long transit time through the image, you can improve the read rate by setting the Character height filter to ignore license plates until they appear at the right height in the image.
- It is important to configure this setting for fixed and mobile parking scenarios where read accuracy is vital.
- If the SharpV is configured for dual-lane plate reading, the characters must be from 10 to 40 pixels high. For more information, see Configuring the SharpV to monitor dual lanes.
- The system captures plate reads more accurately if characters are between 25 and 60 pixels high in the images acquired by the ALPR camera. The optimal size of license plate characters is 30 pixels high.
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.
Procedure
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Adjust the Character height filter as required to capture
plates at the required distance.
