To configure the License Plate Recognition RR detection tool, do the following:

  1. Go to the Detection Tools tab.
  2. Below the required camera, click Create… → Category: Vehicle → License Plate Recognition RR.

By default, the detection tool is enabled and set to recognize vehicle license plates.

If necessary, you can change the detection tool parameters. The list of parameters is given in the table:

ParameterValueDescription
Object features
Check in listsYes

The parameter is disabled by default. If you want to use this detection tool to check in lists of vehicle license plates, select the Yes value (see Configuring vehicle license plate recognition based on the created lists)

No
Record objects trackingYesThe metadata of the video stream is recorded to the database by default. To disable the parameter, select the No value
No
Video streamMain streamIf the camera supports multistreaming, select the stream for which detection is needed. Selecting a low-quality video stream reduces the load on the Server
Second stream
Other
EnableYesThe detection tool is enabled by default. To disable the detection tool, select the No value
No
NameLicense Plate Recognition RREnter the detection tool name or leave the default name
Accuracy and performanceMedium accuracy and high performance

Select the accuracy and performance of vehicle recognition:

  • Medium accuracy and high performance—provides medium recognition accuracy and high GPU performance (less load on GPU);
  • High accuracy and medium performance—provides maximum recognition accuracy and medium GPU performance (high load on GPU)
High accuracy and medium performance
Decoder modeAutoSelect a processing resource for decoding video streams. When you select a GPU, a stand-alone graphics card takes priority (when decoding with NVIDIA NVDEC chips). If there is no appropriate GPU, the decoding will use the Intel Quick Sync Video technology. Otherwise, CPU resources will be used for decoding
CPU
GPU
HuaweiNPU
TypeLicense Plate Recognition RRName of the detection tool type (non-editable field)
Advanced settings
Event timeout0Specify the time in seconds after which the alarm must be generated after recognizing a license plate in the frame. If the value is 0, the alarm will be generated after the track with a license plate is lost. The value must be in the range [1, 3600]
Frame size change1920

The analyzed frames are scaled down to a specified resolution (1920 pixels on the longer side) by default. The value must be in the range [640, 10000]. The following algorithm is used:

  • If the longer side of the source image exceeds the value specified in the Frame size change field, it is divided by two.
  • If the resulting resolution falls below the specified value, the algorithm stops and this resolution will be used further.
  • If the resulting resolution still exceeds the specified value, it is divided by two until it is less than the specified resolution.

For example, the source image resolution is 2048*1536, and the specified value is set to 1000. In this case, the source resolution will be halved two times (512*384), as after the first division, the number of pixels on the longer side exceeds the specified value (1024 > 1000). If detection is performed on a higher resolution stream and detection errors occur, we recommend reducing the compression.

Minimum recognition quality, in %80Specify the minimum quality of license plates recognition as a percentage. The higher the minimum recognition quality, the fewer false alarms. The value must be in the range [0, 100]
Speed detectionOff

Select from the list the mode for determining the speed unit of vehicles.

For the correct displaying of the speed measurement unit, you must create the MEASUREMENT_UNIT system variable (see Appendix 9. Creating system variable) and specify the value:

  • 0—to display kmph;
  • 1—to display mph.
Kmph
Mph
Speed detection area height0

Before you specify the value of the Speed detection area height parameter, you must select the area in the preview window (see Recommendations for configuring the speed detection area). 

Specify the speed detection area height in meters. The value must be in the range [0, 500]

Speed detection area width0

Before you specify the value of the Speed detection area width parameter, you must select the area in the preview window (see Recommendations for configuring the speed detection area). 

Specify the speed detection area width in meters. The value must be in the range [0, 500]

Basic settings
Algorithm for detecting vehicle directionBy LP coordinatesThe By LP coordinates algorithm is used by default. It works as follows: if the coordinates of the vehicle license plate shift from top to bottom (the vehicle moves towards the camera) and if the coordinates of the vehicle license plate shift from bottom to top (the vehicle moves away from the camera). Select the By LP scale change parameter if in the Surveillance window, the scale of the vehicle license plate increases (the vehicle moves towards the camera) and if the scale of the vehicle license plate decreases (the vehicle moves away from the camera)
By LP scale change
Info on unrecognized LPs

Yes

The parameter is disabled by default. If it is necessary to determine all possible information from unrecognized license plates, select the Yes value

No
ModeCPU

Select the processor for the detection tool operation—CPU or NVIDIA GPU (see Selecting Nvidia GPU when configuring detection tools).

It may take several minutes to launch the algorithm on NVIDIA GPU. You can use caching to speed up future launches (see Optimizing the operation of License Plate Recognition RR and Vehicle Recognition RR on GPU)

Nvidia GPU 0
Nvidia GPU 1
Nvidia GPU 2
Nvidia GPU 3
Vehicle recognitionYes

The parameter is disabled by default. If you want to search for vehicles in the archive by vehicle make, model, vehicle class, or other specified criteria, select the Yes value (see Search by LPs)

No
Country selection
Country 1 name

Armenia, Argentina, Austria, Azerbaijan, Bulgaria, Brunei, Belarus, Brazil, Belgium, China, Cyprus, Ivory Coast, Czech Republic, Germany, Colombia, Denmark, Estonia, Egypt, Finland, France, Georgia, Greece, Croatia, Hungary, Indonesia, Ireland, Italy, Kyrgyzstan, Kazakhstan, Lithuania, Luxembourg, Latvia, Malta, Malaysia, Mexico, Moldova, Myanmar, Netherlands, Peru, Poland, Portugal, Romania, Serbia, Russia, Sweden, Slovakia, Slovenia, Turkmenistan, Tajikistan, Spain, Ukraine, USA (starting with Detector Pack 3. 12), Uzbekistan, Vietnam, Not used

In the corresponding fields, select from the list one or more countries whose license plates you want to recognize
Country 2 name
Country 3 name
Country 4 name
Country 5 name

In the window, specify the area in which license plate detection and recognition will be performed. You can adjust the area by moving the anchor points . 

  • For convenience of configuration, you can "freeze" the frame. Click the  button. To cancel the action, click this button again.
  • The detection area is displayed by default. To hide it, click the  button. To cancel the action, click this button again.
  • To delete the selected area, click the button.

To save the parameters of the detection tool, click the Apply  button. To cancel the changes, click the Cancel  button.