License plate recognition (LPR) is a technology that uses optical character recognition on images to read vehicle registration plates. It can use existing cameras, road-rule enforcement cameras, or cameras specifically designed for the task.
LPR is also used by police forces around the world for law enforcement purposes, including to check if a vehicle is registered or licensed. electronic toll collection on pay-per-use roads and as a method of cataloguing the movements of traffic for example by highways agencies. With the advent of LPR based sensor cameras, it is used in high speed roadways as well.
LICENSE PLATE CAPTURE OPTIMIZATION
- Application — LPR sites should be used where traffic stops or
moves less that 25mph (e.g. traffic stops, toll booths, vehicle gates,
stop signs). 3VR LPR support US and international plates.* - Cameras — Analog or IP cameras. For IP cameras, video quality
must be set to “highest” (if there is no video quality setting, set to
lowest compression). - Lighting — Uniform lighting is ideal. Outdoor lighting situations
should employ wide dynamic range cameras. Back lighting (bright
conditions behind the car) will negatively affect performance.
- Mounting — Choose either vertical or horizontal mounting option:
- Vertical — Camera should be directly above the lane of traffic. Use the Mounting chart below.
- Horizontal — Camera should be mounted at the same height as the license plates. Use the Mounting chart below.
- Diagonal — (both at the side and above) mounting is not recommended.
- Field of View — For accurate recognition of North- American
plates, license plate characters should be 30 pixels high or greater,
or use the Field of View chart below for reference.
Good lighting conditions Bad lighting conditions
* Use 3VR Standard LPR for stopped U.S. plates and 3VR Premium LPR for moving or international plates
INSTANT LPR FEEDBACK
For instant feedback on license plate capture, after inputting the live feed and installing the LPR plug-in on the appropriate camera, conduct a drive-through on that camera. Go
to the Monitor panel and choose to view the “License Plate” event type.
3VR LPR Plug-in Version1.0.1.1547 is supported with 3VR Releases 7.3.2.x and 8.1.1.x above. Please download at partners.3vr.com/?q=3vr-plug-ins
**Specifications to change without notice. Visit www.3vr.com for up-to-date materials and information about 3VR products.**