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Configuration Article | CA-20201130-TP-08 VDG Sense | Setup | Profiles | CarR  |
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CarR is the realtime ANPR or license plate recognition of VDG Sense. It can be enabled in the Profiles setup tab and is only available if the server has a license for one or more CarR cameras. This article explains how to configure a camera for fast ANPR. For more information on camera placement check the VCA pages about CarR./wiki/spaces/KB/pages/932937798
With CarR activated the following two events can occur:
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License Match: License plate is matched / recognized which means the license plate is known in the Sense Database/wiki/spaces/KB/pages/936673549.
CarR Setup
CarR is enabled and configured per camera in the CarR subtab of the Profiles menu, see below:
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Follow the guidelines for CarR camera placement, read here.
Configure parameters in General, Storage and Motion tab to ensure only frames are processed in which a license plate is visible (before it is scanned); less frames is faster performance.
Determine which countries need to be scanned, this is done in the Server tab and the profile Countries parameter
Fine-tune CarR profile parameters Min/Max Character size, Confidence and Max process time (explanation below)
Determine how many events are generated for the same license plate use Match Distance and License Plate Found Distance parameters (explanation below)
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CarR Countries
This field displays the activated countries. A double-click on the field shows a dialog with available countries. Check countries on or of to enable these for this profile. The activated countries can be configured in the ’Servers’ tab. For more information, check the Installed CarR Countries page.
Perspective Correction
LPR perspective correction is a method of changing the image of a CarR device in such a way that the angle of the field of view benefits the License Plate Recognition (LPR) algorithm. The perspective correction can be utilized in scenarios where due to the position of the CarR device, license plates are being misidentified or even missed and where the external conditions are often good and constant. For example, vehicles don’t drive too fast, which makes it easier to capture the vehicle at a fixed position. The best recognition is achieved if the guidelines for CarR cameras are followed, the guidelines can be found here: CarR Guidelines,
However, in some situations, setting up a CarR device in such a way is not possible, for example due to architectural difficulties or enforcement of certain limitations. In these situations, the LPR perspective correction may help to create a viable image that the LPR algorithm can use. An example of an image that is taken at the entrance of a parking lot is shown in below:
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In the right column, the perspective correction can be configured using the following steps:
Enable Perspective Correction by clicking the checkbox.
Use the green rectangle in the reference image to identify the area in which license plate will appear.
Set the actual size of the area in millimeters.
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