The present invention is related to elevator door detection, and in particular to computer vision methods of detecting elevator door position. 
Elevator door control is an important aspect of elevator safety.  A variety of sensors and systems have been developed to sense the position of elevator doors, as well as to detect any obstacles that would prevent the elevator doors from closing.  Traditionally, infrared sensors or proximity sensors installed within each elevator cab provide feedback to a controller regarding the position of the doors and whether any obstacles had been detected between the doors.  However, these systems require the installation of dedicated sensors within the elevator, and incur expenses associated with maintaining the operational state of the sensors. 
In addition, buildings are increasingly relying on video surveillance to provide building security, access control, and other functions.  As part of these systems, it is becoming increasingly common to include video surveillance in, or in close proximity to, elevator cabs.  Therefore, it would be beneficial to develop a system that could make use of the video surveillance devices already employed in these buildings to provide the feedback necessary to safely and efficiently control the operation of elevator doors without the use of dedicated sensors.