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For the License Plate Recognition IV to work, you must activate the license (see Activating the license for the License Plate Recognition IV in Windows OS, Activating the license for the License Plate Recognition IV in Linux OS). |
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| Parameter | Value | Description | |||||
|---|---|---|---|---|---|---|---|
| Object features | |||||||
| Check in lists | Yes | 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 tracking | Yes | The metadata of the video stream is recorded to the database by default. To disable the parameter, select the No value | |||||
| No | |||||||
| Video stream | Main stream | If 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 | |||||||
| Enable | Yes | The detection tool is enabled by default. To disable the detection tool, select the No value | |||||
| No | |||||||
| Name | License Plate Recognition IV | Enter the detection tool name or leave the default name | |||||
| Decoder mode | Auto | Select 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 | |||||||
| Type | License Plate Recognition IV | Name of the detection tool type (non-editable field) | |||||
| Advanced settings | |||||||
| Event timeout | 1 | Specify the time in seconds after which an event must be generated after recognizing a license plate in the frame. The value must be in the range [1, 3600]. If the value is 0, an event will be generated after the track with a license plate is lost | |||||
| Frame size change | 1920 | The analyzed frames are scaled down to a specified resolution (1920 pixels on the longer side) by default. The following algorithm is used:
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| Initiate event in (sec) | 1 | Specify the time in seconds after which an event must be generated after recognizing a license plate in the frame. The value must be in the range [0, 3600]. If the value is 0, an event will be generated after the track with a license plate is lost | GDPR policy | - | By default, on the layout and in the archive, the characters of a license plate are completely hidden "GDPR ON". To display the characters of a license plate, you must enter a value: "-"—hide all characters (default value), " (blank field of a parameter value)"—show all characters, "N-"—hide the first N characters, "-N"—hide the last N characters, where N is the number of characters | ||
| Maximal number of characters in LP | 10 | Specify the maximum number of characters in the license plate. The value must be in the range [1, 20] | |||||
| Minimal number of characters in LP | 5 | Specify the minimum number of characters in the license plate. The value must be in the range [1, 20] | |||||
| Minimum recognition quality, in % | 80 | Specify the minimum quality of license plates recognition as a percentage. The higher the minimum recognition quality, the fewer false events. The value must be in the range [0, 100] | |||||
| Tracker timeoutTrack retention time (sec) | 3 | Specify the time in seconds after which the vehicle track is considered lost. The value must be in the range [0, 3600].
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| Basic settings | |||||||
| Algorithm for detecting vehicle direction | By LP coordinates | The 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). | |||||
| By LP scale change | |||||||
| Maximum LP width | 10 | Specify the maximum and minimum width of the license plate as a percentage according to the actual size of the license plate in the frame. The value must be in the range [0, 100].
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| Minimum LP width | 1 | ||||||
| Processing unit | CPU | Select a processor for the detection tool operation (see Selecting Nvidia GPU when configuring detectors).
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| Nvidia GPU 0 | |||||||
| Nvidia GPU 1 | |||||||
| Nvidia GPU 2 | |||||||
| Nvidia GPU 3 | |||||||
| Country selection | |||||||
| Country name |
| Select from the list the country whose license plates you want to recognize and select the recognition accuracy:
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To save the parameters of the detection tool, click the Apply 
button. To cancel the changes, click the Cancel 
button.
If necessary, you can create can create and configure the necessary detection sub-tools on the basis of the License Plate Recognition IV (see see Standard sub-detectors).
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