Configuring the VT module

Configuring the VT program module

Configure the VT program module as follows:

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

2. Set the Zooming checkbox checked to increase the plate recognizing speed on mega-pixel video cameras without loss of recognizing quality (1).

   This check box 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 recognizing speed is increasing:

   1. 2 times if the value of the Zone width parameter is more than 150 pixels;
   2. 4 times if the value of the Zone width parameter is more than 400 pixels;
   3. 8 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 video camera be 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 will be performed in the same stream it was started. It is the default value.

   2. If the value of the Number of streams for frame processing field is 1, recognition will be 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 will be performed in two or more streams simultaneously to the process that starts it. However, in this case, 1 license channel is used for each stream.

      Attention!

      The specified number of streams should 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 whose license plate number could not be recognized.

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

   Attention!

   Fine tuning of SDK is to be performed only with the help of AxxonSoft 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).

   The current SDK version can be found 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.

   Also, the current SDK version can be found 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 program module is now configured.

Tracking the disappearance of the recognized number

It is possible to track the disappearance of the recognized number. If the recognized number disappeared from the camera field of view and was not recognized again within the specified time, the lost number 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 tweaking 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 distribution kit for activating the GPU for the VT module from the AxxonSoft website from the Axxon PSIM downloads page.
2. Unpack the downloaded archive.
3. On the computer with the installed Auto PSIM software package, place all files of the downloaded archive in a folder at the address: C:\Program Files (x86)\<Auto PSIM installation directory>\Modules64\UrmLpr\VIT_2.16.0.
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 launch (initialization) time of the license plate recognition algorithm using a GPU can take several minutes. No license plate recognition events will be received until initialization is completed.