VCA - Abandoned and Removed object

The abandoned and removed object rule triggers when an object has been either left within a defined zone, e.g. a person leaving a bag on a train platform, or when an object is removed from a defined zone.
The abandoned rule has a duration property which defines the amount of time an object must have been abandoned for or removed, to trigger the rule.

Below is a sample scenario where a bag is left in a defined zone resulting in the rule triggering.

Below is a similar example scenario where the bag is removed from the defined zone resulting in the rule triggering.

Note: The algorithm used for abandoned and removed object detection is the same in each case, and therefore cannot differentiate between objects which have been abandoned or removed.
This arises because the algorithm only analyses how blocks of pixels change with respect to a background model which is constructed over time.