By default, the LPR channel recognizes the LP numbers of all vehicles passing the camera viewing zone: i.e. moving toward the camera and away from the camera. The module can be set to recognize and save the LP numbers of the vehicles moving in certain direction: From the camera, To the camera, Any. The following results can appear as an outcome of the vehicle movement direction recognition: From the camera, To the camera, undefined.

If traffic direction is set, then by default in case if the direction of vehicle movement does not coincide with the specified value, the Entered the oncoming lane alarm event will be created. This event can be disabled. If vehicle movement direction is undefined, the Entered the oncoming lane alarm event is not created.

To select the movement direction for the vehicles to be recognized, do the following:

1. Go to the LPR channel object settings panel, corresponding to the activated module (see Activating the software module used for identifying the plates).
   
2. From the Direction calculation drop-down list (1), select the mode of determining the vehicle's movement direction:
   • by LP position - the direction is determined by the position of the upper part of the LP number. If the upper part of the LP number at the start of tracking is lower than the upper part of the LP number at the end of tracking, then the direction is defined as From the camera, otherwise - To the camera.
   • by LP area - the direction is determined by the license plate area. If the LP area at the start of tracking is larger than the LP area at the end of tracking, then the direction is defined as From the camera, otherwise - To the camera.

   • by SDK - the direction is determined by the SDK.

     If the direction of movement is detected incorrectly or the license plate recognition stops, it is recommended to select the by LP area mode.

     
     

3. From the Direction drop-down list (2), select the traffic direction relative to the camera in which it is necessary to recognize the LP numbers.

   For the IntLab module, the direction of carriages in the camera view is selected from left to right or from right to left (see Setting up the IntLab module).

   
   

4. Set the Undefined checkbox (3) to display the direction as Undefined in the Vehicle Tracer module, if it is impossible to determine the vehicle direction.

5. If the from the camera or to the camera value is selected in the Direction drop-down list, the Record violation checkbox becomes available (4). By default this checkbox is set. That means that in case if the direction of vehicle moving is not coincide with the specified value, the Entering an oncoming lane alarm event will be created. If this event should not be created, unset the checkbox.

   The following variations are possible depending on selecting the traffic direction: if the to the camera direction is selected and the Record violation checkbox is set the recognition is performed in both direction; if traffic is performed from the camera the alarm event will be created; if the from the camera direction is selected and the Record violation checkbox is set the recognition is performed in both direction; if traffic is performed to the camera the alarm event will be created; if the to the camera direction is selected and the Record violation checkbox is not set the recognition is performed only in direction to the camera; if the from the camera direction is selected and the Record violation checkbox is not set the recognition is performed only in direction from the camera;

   
   

6. Click Apply (5).

The vehicle movement direction is now selected.