*ObjectR Basic – Area of Interest

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Technical Article | TA-20201002-TP-11 VDG Sense | Video Content Analyses | ObjectR Basic Open

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Note: ObjectR Basic is not available in VDG Sense 2.5 or higher!

An area of interest is a square, a rectangle, or another multi-sided shape drawn within the camera’s field of view that specifies where the system should monitor for events. For example, an airport’s security team can create an area of interest so that a response is triggered when a person walks into an area that is too close to a restricted part of the runway. Below are all event types that are associated with the area of interest events.

Enters
Enters events occur when an object enters an area of interest from any direction within the camera’s field of view. An alert is triggered when an object enters the perimeter of the area of interest. Enters events are generally set up in areas where there is little activity expected, and an alert needs to be generated whenever an object enters the area. For example, a rule could be created to trigger an alert when someone enters an area of interest near a restricted room. Be aware of the distinction between enters events and appears events.

Enters events occur whenever an object enters the area of interest, if the object has already been detected within the camera’s field of view before entering the area. An alert would not be triggered for an enters event if the object involved in the event was inside of the area of interest the first time it appeared within the camera’s field of view.

Inside

Exits
Exits events occur when an object exits the perimeter of an area of interest in any direction. Be aware of the distinction between Exits events and Disappears events.

Disappears from partial view events occur when an object disappears within an area of interest. In other words, the last time the object was tracked within the camera’s view, the object was present in the area of interest. This can occur when an object disappears through a doorway within the area of interest or behind scenery.

Exits events do not include objects disappearing through doorways and windows or behind scenery within the area of interest. The object must exit through the perimeter of the area of interest in order to trigger an alert.

Appears
Appears events occur when an object appears in an area of interest without appearing within the camera’s field of view previously. An example of such an event is a person entering a doorway around which an area of interest is drawn. Because the first time he object was detected was when the person entered the doorway, an Appears alert is triggered. Objects can also ”appear” in areas of interest drawn around windows, trees and other scenery within the camera’s field of view, and architectural features, such as the corner of a building.

There is an important distinction between Appears events and Enters events. See Enters.

Disappears
Disappears events occur when an object disappears from the camera’s field of view, having last been detected within an area of interest. In other words, the last time ObjectR detected the object within the camera’s field of view, it was present in the area of interest.

For example, a Disappears event could be created to detect a person exiting through a restricted doorway within part of a camera’s field of view. Objects can also disappear from areas of interest drawn around trees and other scenery within the camera’s field of view, and architectural features, such as the corner of a building or a window.

There is an important distinction between Disappears events and Exits events. See Exits.

Taken away
Taken away events occur when an object is removed from an area of interest. The event is triggered when an object has been absent from the area of interest for 5 seconds or more.

Events of this kind are typically set up to detect theft and items that transition from being stationary to being in motion.

Left Behind
Left behind events occur when an object is left within an area of interest. For an alert to be triggered, the object must be inside and remain stationary within the area of interest for 13 seconds or more. Events of this kind are typically set up to detect suspicious packages and bags that transition from being in motion to being stationary.

An area of interest event should be used if a left object represents a security-related event in only part of the camera’s field of view.

Loiters
Loiters events occur when an object remains within an area of interest for a user-specified period of time. A different loitering time can be specified for each event. Most often, loitering rules are set up to detect people staying in an area too long. If you want ObjectR to detect objects remaining in an area of interest, it is recommended that you create a Left behind event in addition to a loitering event, because Loiters events trigger alerts for moving objects only.

If a moving object becomes stationary before the loitering time elapses, a Loiters alert will not be triggered. For example, if you set up a Loiters event to detect vehicles parking in a restricted area, you will probably miss events, because once a vehicle parks, it is no longer in motion and will not trigger a Loiters alert. The same is true for Loiters that are set up to detect people loitering. If a person sits down or stands still, a Loiters alert will not be triggered.