Documentation for Auto PSIM 1.0.1.

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Attention!

To ensure the correct operation of the VT module, the current Windows user must have read and write access to the following directories and files:

  • <Auto PSIM installation directory>\Modules\UrmLpr\
  • <Auto PSIM installation directory>\Modules64\UrmLpr\
  • C:\ProgramData\VIT\LprPresetDemo\presets.xml

Configuring the VT software module

Configure the VT program module as follows:

  1. Go to the settings panel of the VT module object that is created on the basis of the LPR channel object.

  2. Set the Zooming checkbox to increase the license plate recognizing speed on mega-pixel cameras without loss of recognizing quality (1).
    This checkbox is relevant when the value of the Zone width parameter is more than 150 pixels (see Setting up the detection of the LPR channel). The zone is an image from the corresponding camera. The recognition speed increases:

    1. Two times if the value of the Zone width parameter is more than 150 pixels;
    2. Four times if the value of the Zone width parameter is more than 400 pixels;
    3. Eight times if the value of the Zone width parameter is more than 800 pixels.
  3. To prevent the loss of processed frames, it is recommended that each megapixel of the camera is processed in a separate stream. If there is a loss of frames, then it is necessary to increase the number of streams in the Number of streams for frame processing field (2):

    1. If the value of the Number of streams for frame processing field is 0, recognition is performed in the same stream it is started. It is the default value.

    2. If the value of the Number of streams for frame processing field is 1, recognition is performed in the parallel stream to the process that starts it. This is the recommended value.

    3. If the value of the Number of streams for frame processing field is 2 or more, recognition is performed in two or more streams simultaneously to the process that starts it. However, in this case, one license channel is used for each stream.

      Attention!

      The specified number of streams must not exceed the number of CPU cores on the server.

  4. From the License type drop-down list (3), select the type of license used:
    • default—the license type is determined automatically;
    • fast—25 FPS;

    • slow—6 FPS.

      Attention!

      If you select the license type that is not in the key, then license plate recognition will not work.

  5. Set the Generate unrecognized LP event checkbox (4), if it is necessary to generate a NOT DETECTED event for vehicles which license plate number could not be recognized.

  6. Perform fine tuning of SDK if required (5) (see VT module object settings panel).

    Attention!

    You must perform fine tuning of SDK only with the help of AxxonSoft technical specialists!

    When fine tuning the SDK parameters VodiCTL_VPW_DYNAMIC_WITH_DUPLICATE, VodiCTL_VPW_DYNAMIC_OUTPUT_TIMEOUT and VodiCTL_VPW_DYNAMIC_OUTPUT_FRAMECOUNT, the values of the corresponding fields of the LPR channel also change (for details, see Setting up the display of LP recognition results).

    You can find out the current SDK version by the name of the VIT_<SDK version> folder, for example:

    • for x32: <Auto PSIM installation directory>\Modules\UrmLpr\VIT_2.16.0.
    • for x64: <Auto PSIM installation directory>\Modules64\UrmLpr\VIT_2.16.0.

    You can also find out the current SDK version using the vpwfetch.exe -v command in the Windows command line, while in the corresponding folder.

  7. Click Apply button (6) to save the changes.

The VT software module is now configured.

Tracking the disappearance of a recognized license plate

It is possible to track the disappearance of the recognized license plate. If the recognized license plate disappeared from the camera field of view and was not recognized again within the specified time, the lost license plate event will be generated. To enable this feature, in the VIT.TimeoutLostNumber parameter, set the time in milliseconds after which the lost number event will be generated (for details, see Registry keys reference guide, for more information about working with the registry, see Working with Windows OS registry).

To ensure the operation of this feature, it is necessary to set the true value for the VodiCTL_VPW_DYNAMIC_ENABLE parameter (see The VT module object settings panel).

License plate recognition when there are problems with templates or templates are absent

It is possible to interpret recognized characters as text if, for example, there are problems with template recognition or if the recognized license plates don't match known templates.

To ensure the operation of this feature, it is necessary to set the true value for the VodiCTL_VPW_TREAT_SYMBOLS_AS_TEXT parameter (see The VT module object settings panel).

Using a GPU for VT license plate recognition

By default, only the CPU resources are used. To enable the usage of the GPU computing resources, do the following:

  1. Download the TensorRTCudaCudnn_SDK_Installer.zip distribution kit from Hotfixes of Axxon PSIM and vertical solutions.
  2. Unpack the downloaded archive.
  3. Install this software on the computer that has Auto PSIM installed.
  4. On the settings panel of the LPR channel object, select a GPU for license plate recognition (see Selecting a device for license plate recognition).

The start time (initialization) of the license plate recognition algorithm using a GPU can take several minutes. No license plate recognition events are received until initialization is complete.

If recognition doesn't start, delete the cache files from the VT_Cache folder located at C:Windows and restart Axxon PSIM. After that, wait for the caching process to complete. As a result, cache files appear in the VT_Cache folder, and GPU is used for recognition.

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