Configuring the VI detection of crowd module

Configuration of the VI detection of crowd module includes general settings and configuration settings: detection zone, configuration parameters, and detector characteristics.

General settings of the detector

1. Go to the settings panel of the VI detection of crowd object that is created on the basis of the Camera object on the Hardware tab of the System settings window.
   
2. In the Frames processed per second [1, 100] field, specify the number of frames in the range  from 1 to 100 that the detector processes per second. The default value is 12 (recommended). You can specify only a positive integer. If you enter a number outside the range 1–100, it is automatically changed to the nearest border value. If you leave the field blank, it automatically returns to the default value when you save the settings.
3. Set the Show objects on image checkbox if you want to outline the detection zone with a red border on the video surveillance monitor when a crowd detection event is generated. The detection zone is specified in the detector settings on the Select area tab.
4. From the Detection filtering drop-down list, select the filter that you want to use: Object filter, Object counting filter, Do not use filter (default). You can configure filters on the Postprocessing tab of the Detection settings window.
5. Click the Configuration setup button. As a result, the detector settings window opens.

The Select area tab

1. In the Detection settings window, on the Select area tab, click the Stop video button to pause the video.
2. By default, the entire frame is outlined with a red border as a detection zone. You can change the borders of a zone by clicking its number in the list on the right and highlighting it in blue color.
   
3. To rename the detection zone, enter a new name in the field to the right of its number. The new name appears in the zone caption on the video image.
   

   Note

   You can specify only one detection zone.

   To delete a detection zone, click the button to the right of the zone name.

   After you delete a zone, save and reopen the settings, a default zone is automatically added.

   If you specify an incorrect zone, it is automatically replaced with a default zone after you save and reopen the settings.

4. To save all changes, click the Apply configuration changes button.
5. To start video playback, click the Start video button.

The Parameters tab

1. Go to the Parameters tab of the detector settings window. This tab displays the parameters of the used configuration. If you don't need to change the configuration, skip steps 2 and 3 and go to the next tab.
   
2. To use the custom configuration, click the Load configuration from file button.
3. In the standard Windows search window that opens, specify the path to the prepared configuration file in JSON format.

The Crowd detection tab

1. Go to the Crowd detection tab.
   
2. In the Head size [3, 100] field, specify in the range from 3 to 100 what part of the video image height is the human head. The specified fractional value is rounded to an integer value when you switch to another field or save the settings. The default value is 3.

3. In the Occupancy field, specify as a percentage the share of the detection zone area that must be filled in order for the detector to record the beginning of the Crowd event. If the occupancy remains longer than the time threshold specified in the Reaction time (s) field, the Crowd alarm event is generated on the detector. The default value is 50.

4. In the Reaction time (s) field, specify in seconds the time interval after which the Crowd alarm event is generated on the detector if the value of the Occupancy parameter remains equal to or above the set threshold. If during the specified period of time the value of this parameter drops below the threshold value, then the time counting stops and the counter is reset to zero. The default value is 100.

5. In the Time between alarms (s) field, specify in seconds the frequency of the Crowd alarm event generation. The default value is 180.

6. In the Number of analytics streams field, specify the number of video streams that are used for neural network analytics. The default value is 4.

The Postprocessing tab

You can use this tab to configure object filters or object counting filters according to the option selected from the Detection filtering drop-down list in the basic settings of the detector.

Object filter

1. To enable the object filter, select Object filter from the Detection filtering drop-down list in the basic settings of the detector.
2. Go to the Postprocessing tab.
3. From the Object filter list on the left, select one or more objects. If these objects are detected in the frame, the detector events are filtered. The events aren't displayed in the event viewer and on the screen.
   
   

   Note

   To remove the filter, click it again.

4. To apply the filter, click the Apply filter configuration button.

Object counting filter

1. To enable the object counting filter, select Object counting filter from the Detection filtering drop-down list in the basic settings of the detector.
2. Go to the Postprocessing tab.
3. Click the Add count filter button. In the section on the right, select one or more object counting filters.
   
   
4. In the Min and Max fields, set the lower and upper threshold values for each object counting filter. If the number of objects of a given type in the detection area is within this range, the detector generates an event that is also displayed in the event viewer and on the screen. If the number of objects is greater or less than the set range, or there are no objects at all, then all events are filtered out and aren't displayed in the event viewer or on the screen.
   

   Note

   To remove the filter, click the cross to the right of it.

5. To apply the filter, click the Apply filter configuration button.

Click the OK button to save all settings of the detector. The Detection settings window closes, and you return to the detector settings panel.

To save all changes, click the Apply button on the settings panel of the VI detection of crowd object.

Configuring the VI detection of crowd module is complete.