LPR Camera Not Detecting License Plates

I installed a Viewtron LPR-IP4 license plate recognition camera. My other LPR cameras are reading plates, but this one does not show any plates in Target Detection on the Live page. I already tried zooming in, adjusting the plate size and even remounting the camera. Why is my LPR camera not detecting license plates?

Check the Blocked Area setting first. If a Blocked Area is turned on and it covers the same part of the image as your Detection Area, the camera ignores every plate in that zone. On a recent install, the camera was not reading a single plate. As soon as I cleared the Blocked Area, plates started showing up in Target Detection right away.

1. What is the Blocked Area on an LPR camera?

The Blocked Area is a part of the image where you tell the LPR camera NOT to look for license plates. It is meant for things like a parking spot where cars sit all day, so the camera does not keep logging the same parked car.

The Detection Area is the opposite. It is the zone where the camera looks for plates. If the Blocked Area overlaps the Detection Area, the blocked part wins and those plates are ignored.

2. How do I clear the Blocked Area on the LPR-IP4?

Log into the camera from a web browser (Chrome, Firefox or Safari), then:

1. Click Config, then go to Event and select License Plate Detection.
2. Under Alarm Area, look at the Blocked Area row. If the box is checked, a blocked zone is turned on.
3. Select the Blocked Area and click Clear to remove the blocked zone. Uncheck it if you do not need one.
4. Click Save.
5. Go back to the Live page and drive a car through the detection zone. You should now see plates in Target Detection.

If you do need a Blocked Area, draw it only over the part of the image you want ignored, and make sure it does not overlap the Detection Area where cars pass the camera.

3. What else stops an LPR camera from reading plates?

If the Blocked Area is clear and the camera still does not read plates, check these next:

• Mounting angle. The less horizontal and vertical angle, the better ALPR works. A camera mounted very high and looking down at a steep angle can still record clear plate video (LPC), but automatic plate recognition (ALPR) does much better from a lower mount. Keep the vertical tilt at about 15 degrees or less.
• Zoom. Before you move the camera, try zooming the motorized lens in on the detection zone to make up for a high angle.
• Target Size Filter. The Min and Max size settings tell the camera how big a plate can be in the image. If the plates in your live view are smaller or bigger than that range, they get filtered out. Adjust it as a test.
• Detection Area placement. Draw the zone around the spot where you want plates logged. For example, if cars wait at a stop line, put the zone just past the line so you only log cars as they drive through.

Related

• Viewtron LPR-IP4 license plate recognition camera
• Recommended setup for LPR cameras, including mounting angles
• License plate reader camera systems

Still have questions? Call our technical support team at 561-433-8488 or email info@cctvcamerapros.net.