Articles on: Artificial Intelligence

How to deploy an LPR Camera

License Plate Recognition (LPR) cameras are a valuable tool for enhancing security and monitoring traffic in various environments. Proper deployment is crucial to ensure optimal performance and accurate license plate recognition. In this guide, we'll cover the key steps and considerations for setting up an LPR camera. LPR should only be enabled for specific cameras which are properly setup to ensure good results.

Hard Constraints

Maximum distance between camera and license plate of 15 feet with minimum 1080p resolution.
Maximum vertical and horizontal angle of 20 degrees. To verify this angle, check that at a 10 foot distance between the license plate and the camera, the camera is no more than 3 feet above, below, to the left or to the right of the license plate
Maximum Vehicle Speed of 5 mph (parking lot speeds will work, road speeds will not)
License plate MUST BE visible and human readable in Dashboard for at least 2 full seconds

LPR Camera Constraints

Deployment Guidelines

Ceiling-mount or pole-mount the cameras so that the vertical angle between the vehicle and cameras is between 0° and 30° to the road surface.

Verticle angle for camera mounting

Mount the camera so that the horizontal angle between the vehicle and the camera is between 0° and 25°.

Horizontal angle for camera mounting

Ensure that the vehicles are traveling at less than 30km/h (18mph) when entering or exiting the LPR zone.

Maximum speed of vehicles during LPR

Ensure you position the camera so that the view of the vehicle license plate is not obstructed by any entry/exit barriers.

No obstruction of license plate

Make sure the camera is mounted at least 1 meter above the headlight level, to ensure the cameras do not suffer glare from the vehicle lights.

Mount cameras above the headlight beams

Factors for Successful LPR

CategoryPotential IssuesMitigation
vehicleSpeed of travelCapture images when vehicle is moving slowly or has stopped
Size and position of license plateConfigure the recognition area
locationExtraneous detail in the camera viewPosition the cameras to exclude unwanted detail where possible
Other moving objects in areaUse optical zoom to crop out areas of the view where unwanted moving objects might be expected
Lighting conditionsSelect a camera that functions well in the available lighting conditions
cameraCamera mounted too high/lowAim for a vertical angle of between 0° to 30°
Excessive horizontal angle to licenseAim for a horizontal angle of between 0° to 25°
Camera mounted too far from the intended license plate detection areaReposition the camera, or use optical zoom to focus on the relevant area

Enabling LPR on AI Camera

Click “Go to Configuration”, then go to “Model Parameters” Tab
To enable LPR, toggle the LPR button on. Then go to “Regions” tab.

Enabling LPR on AI Camera

Toggle Regions button on and click on “Configure new region”

Configure Region

Then click continuous points on the image to create your region. Make sure the region end point is the same as the start point to close the polygon.

Draw Region

Click next and give the region a name in the next step.

Configure LPR

Click on the leftmost icon to indicate this region is for LPR and then click on + icon to add the region.

LPR has now been set up.

Updated on: 04/04/2024

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