Setting up the Camera of recognition upon request module

The LPR channel enables license plate recognition upon request using the Camera of recognition upon request object. This object allows you to configure the camera so that it captures and sends a video image to the recognition module after a specific trigger activates. It can be, for example, a macro, a script, or some event. 

Configure the recognition upon request as follows:

1. Go to the Camera of recognition upon request settings panel created on the basis of the LPR channel object.
   

2. From the Camera drop-down list (1), select the camera that will work upon request. 

   Note

   • You can select the same camera in the several Camera of recognition upon request objects.
   • When you select a camera in the settings of the Camera of recognition upon request object, it becomes impossible to select any camera on the settings panel of the LPR channel object (see Selecting the video cameras to work with the LPR channel).

3. Set the Search area (2) checkbox to enable setting the search area border of the license plate in the frame.

   1. In the Left, Top, Right, and Bottom fields, set manually or using the  button (3), by clicking which, the interactive interface for setting search area borders of the vehicle license plate appears—a video image from the corresponding camera. You can set an arbitrary search area using the segments. To select a rectangular search area, set the Rectangular zone checkbox (5).

      Note

      The values in the Left, Top, Right, and Bottom fields are specified as percentages of the surveillance window.

4. Set the maximum and minimum size of license plates:

   1. Set the Max.width and Max.height parameters manually or using the  button (4), by clicking which, the interactive interface for setting the zone parameters appears—a video image from the corresponding camera.

      
   2. When required, click the Stop video button, select the required area using the left mouse button, and then click the OK button. 
      
      Results of setting zone parameters will automatically appear in the Max.width and Max.height fields.
      Set the Min.width and Min.height parameters in the same way.

5. For the Frame count (6) parameter, set the number of frames that are analyzed when recognizing the license plate.

   Note

   We recommend setting the number of frames to no more than 1.

6. Set the Zooming (7) checkbox to speed up the license plate recognition for megapixel cameras without any quality loss. 

   Note

   This checkbox is relevant only when the width of the Search area is more than 150 pixels. The recognition speed increases:

   • 2 times if the value of the Width parameter is more than 150 pixels;
   • 4 times if the value of the Width parameter is more than 400 pixels;
   • 8 times if the value of the Width parameter is more than 800 pixels.
7. Set the Select with best recognition accuracy checkbox (8) to show the recognition results with the highest accuracy rate, since the bigger LP size doesn't always result in better recognition accuracy. Operates only when using the VT recognition module.
8. Set the Select with biggest LP checkbox (9) to show the result with the biggest LP size. Operates only when using the VT recognition module.
9. From the Priority country drop-down list (10), select the country whose LPs must be shown first. Operates only when using the VT recognition module.
10. Click the Apply button (11).

You can configure the request, which will trigger the camera, in two ways:

1. Using a macro. To do this, go to the Programming tab in Axxon PSIM and select the Macros item in the programming tools tree. A window for creating a macro will open, enabling you to create an event of any complexity that will trigger the recognition upon request. An example of the simplest macro for recognition upon request is shown in the figure. For details on working with macros, see Creating macros.

   

2. Using a script or the IIDK interface. To do this, go to the Programming tab in Axxon PSIM and select the Scripts item in the programming tools tree. A window for creating a script will open, enabling you to create an event of any complexity that will trigger the recognition upon request. For details on working with scripts, see Creating a script. An example of a simple script for working with a camera for recognition upon request is shown below.

   QUERY_CAMERA|ID|RECOGNIZE

   where ID is the ID of the camera in the Axxon PSIM objects tree.

   For details on the IIDK interface, see Axxon PSIM Integration Developer Kit (IIDK).

Setting the license plate recognition upon request is complete.