1. A method of monitoring whether an object of interest is passing through an area within a field of view of a scene observed by a video camera, the method comprising: receiving video data representing the field of view of the scene observed by the video camera; using video analytics to track an object of interest represented in the video data; configuring a detection zone within the area, the detection zone having at least two sides; signaling an occurrence of an event when the tracked object of interest is continually present in the detection zone during a period beginning when the tracked object of interest enters the detection zone on one side and ending when the tracked object of interest leaves the detection zone from a different side; and determining a direction the tracked object of interest traveled through the detection zone by determining which side of the detection zone the tracked object of interest entered and which side of the detection zone the tracked object exited.