Line

The visual element Line is needed for searching the archive by the criterion Object trajectory crossing a virtual line. This visual element sets a virtual line in the field of view of a video camera; instances of something crossing this line will be found in the archive.

The end points of the line are connected by a two-colored dotted line. The direction of the object's motion across the line is indicated by dotted arrows.

By default, the end points of the line have the coordinates (50%, 30%) and (50%, 70%) as percentages of the width and height of the frame, respectively.

To move the end point of a line, position the cursor on the end point and hold down the left mouse button as you move the mouse.

By default, both directions of motion across the virtual line are taken into account when searching the archive. If you do not need to search in a specific direction, click the  button corresponding to that direction.