Previous page Automatic Number Plate Recognition (ANPR)  IntelliVision Automatic Number Plate Recognition (ANPR) Next page

ANPR is a detection tool that reads license / number  plates of vehicles in FoV.

Attention!

C-Werk ANPR / LPS is not compatible with Auto Intellect.

Uninstall the C-Werk VMS  and Auto Intellect,  then reinstall C-Werk.

To configure ANPR, do as follows:

  1. Select the License plate recognition object (1).

  2. If you require using this detection tool for real-time number plate recognition (see Configuring online Vehicle License Plate recognition), set the corresponding parameter to Yes (2).

  3. If you need to enable recording of metadata, select Yes from the Record Objects tracking list (3).
  4. If a camera supports multistreaming, select the stream for which detection is needed. Selecting a low-quality video stream allows reducing the load on the Server (4).

  5. If necessary, enable advanced image analysis (1).

    Yes – improves the quality of recognition under adverse conditions (for example, if the characteristics / settings of the camera do not fully meet the requirements, or in bad weather).  The processing time of the frame increases by 20-30%, depending on its size.  Under normal conditions, this setting does not affect the quality of recognition

  6. To recognize the numbers at sharp angles with respect to the camera, select Yes in the Algorithm of recognition of distorted PL image field (2).

  7. Set the image contrast threshold (3). The default value is 40 . On a high-quality image, increase this value to 50-60. If the image has poor contrast, lower this value. 

  8. In the appropriate fields, select one or more countries for ANPR (4).

    Important

    The more countries you select, the slower the recognition and the greater the likelihood of the recognition error.

  9. Analyzed framed are scaled down to a specified resolution (1, 1920 pixels on the longer side). This is how it works:

    1. If the longer side of the source image exceeds the value specified in the Frame size change field, it is divided by two.

    2. If the resulting resolution falls below the specified value, it is used further.

    3. If the resulting resolution still exceeds the specified limit, it is divided by two, etc.

    Note

    For example, the source image resolution is 2048 * 1536, and the limit is set to 1000.

    In this case, the source resolution will be divided two times (down to 512 * 384): after the first division, the number of pixels on the longer side exceeds the limit (1024 > 1000).


  10. Select the current license type (2).

    License

    Description

    Search in archiveBasic ANPR Search License. Attention! This type of license provides a 30-sec delay between the number recognition and the corresponding event.  (see Vehicle number plate recognition and search).
    25 FPS or 6 FPSThe 25 FPS license has a priority. The 6 FPS license is used only if you have no 25 FPS license. You cannot use the number plate recognition function if you have no FPS licenses purchased.
    25 FPSThe "Fast" license allows you to process video feeds up to 25 fps with a maximum vehicle speed of 150 km/h. You have to obtain an appropriate license to make ANPR work.
    6 FPSThe "Slow" license allows you to process video feeds up to 6 fps with a maximum vehicle speed of 20 km/h. You have to obtain an appropriate license to make ANPR work.
  11. Set the maximum and minimum width of the vehicle number plate as a percentage of the FoV height (3, 5).

  12. Specify the maximum number of recognition threads (4). If the value is 0, the recognition process will occur in the same thread that starts it.

    Important

    It is not recommended to specify a value that exceeds the number of CPU cores.

  13. Specify the minimum percentage of similarity between the recognition result and the corresponding number plate template, for positive LPR result (6). Use this parameter to filter the results by reliability.

  14. Set the number of frames required for LPR / ANPR (7). This is though a necessary condition, but not sufficient for the first output. This condition delays LPR output.  This parameter allows to increase the reliability of the results, as well as to hide false positives.

  15. In the Tracker timeout field, enter a time period in seconds. This is the time before detection starts again after a number plate is recognized (8).

  16. You can configure an ANPR zone in FoV. The zone is resized by moving the anchor points.

    Note

     For your convenience, you can click the  button and configure the mask on a still frame / snapshot. To undo, click this button again.

    Note

    Detection zone is displayed by default. You can click the  button to hide the zone. To undo, click this button again.

  17. Click the Apply button.

Configuration of ANPR  is now complete.

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