Object blocking zones to reduce false alarms in video surveillance systems

• US 20050157169A1
• Filed: 10/20/2004
• Published: 07/21/2005
• Est. Priority Date: 01/20/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Lin, Yun-Ting, Brodsky, Tomas
• Granted Patent: US 8,558,892 B2
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: G08B 13/19602 Image analysis to detect motion of the intruder, e.g. by frame subtraction
• CPC Class Codes: G08B 13/19606 Discriminating between target movement or movement in an area of interest and other non-signicative movements, e.g. target movements induced by camera shake or movements of pets, falling leaves, rotating fan
• CPC Class Codes: G08B 13/19608 Tracking movement of a target, e.g. by detecting an object predefined as a target, using target direction and or velocity to predict its new position
• CPC Class Codes: G08B 13/19652 Systems using zones in a single scene defined for different treatment, e.g. outer zone gives pre-alarm, inner zone gives alarm
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

Blocking zones of a surveillance system are configured to prevent false alarms caused by motion within the zones, while allowing tracking of objects through the zones. An object that first appears within a blocking zone is not considered to be a reportable object until the object leaves the zone. All reportable objects are tracked, without regard to the blocking zones. Objects that remain within their initial blocking zone are not deemed to be reportable objects, and therefore do not generate alarms. If an object initially appears within overlapping zones, the object is not deemed to be reportable until it leaves each of the zones at least once. The blocking zones do not mask the video images, and thus a complete record of activity is available for forensic purposes.

Claims

11. A surveillance system that comprises:

an object recognizer that is configured to recognize an object in a sequence of images,

an object tracker that is configured to track a path of the object,

one or more blocking zones that define select regions within the images, and

an alarm processor;

wherein

the object tracker is configured to;

identify the object as being non-reportable if the object is initially recognized as being within a blocking zone of the one or more blocking zones, and

identify the object as being reportable if the object departs the blocking zone; and

the alarm processor is configured to limit notification of activity to objects that are identified as being reportable.

1. A surveillance method comprising:

obtaining an image from a camera,

detecting an object within the image,

identifying the object as being non-reportable if the object is located within a defined blocking zone of the image,

obtaining subsequent images from the camera,

detecting the object within the subsequent images, and

identifying the object as being reportable if the object is located beyond the defined blocking zone of the image.

2. The surveillance method of claim 1, further including:

identifying the object based on a size of a group of pixels within the video images that exhibit a correlated motion through the sequence of video images.

3. The surveillance method of claim 1, wherein

the blocking zone is defined to correspond to an image of a relatively stationary object that exhibits movement within a defined space.

4. The surveillance method of claim 1, wherein

the blocking zone is defined to correspond to an image of a passageway within which transient objects may appear without appearing beyond the image of the passageway.

5. The surveillance method of claim 1, wherein

the blocking zone is defined to correspond to an image of a reflective surface.

6. The surveillance method of claim 1, wherein

the object is initially identified as being located within a plurality of blocking zones, and

identifying the object as reportable only if the object is detected to have been located beyond each of the plurality of blocking zones in the subsequent images.

7. The surveillance method of claim 1, further including

determining whether to notify a user of the object that is identified as being reportable.

8. The surveillance method of claim 1, further including

tracking motion of the object that is identified as being reportable.

9. The surveillance method of claim 1, further including

recording the images independent of the blocking zone.

10. The surveillance method of claim 1, further including

adjusting a relative location of the blocking zone within the image as the image is modified by a change of view of a device that provides the image.

12. The surveillance system of claim 11, further comprising:

one or more cameras that are configured to provide the images.

13. The surveillance system of claim 11, further comprising:

one or more recorders that are configured to record the images.

14. The surveillance system of claim 13, wherein

the one or more recorders record the images independent of the blocking zone.

15. The surveillance system of claim 11, wherein

the object tracker is further configured to:

determine whether the object is initially recognized as being in one or more other blocking zones, and

identify the object as being reportable only if the object also departs each of the one or more other blocking zones.

16. The surveillance system of claim 11, wherein

the blocking zone includes an associated image region that includes at least one of:

a relatively stationary object that exhibits movement,

a passageway within which transient objects may appear, and

a reflective surface.

17. The surveillance system of claim 16, further including

at least one camera that provides the images,

wherein

the at least one camera provides a controllable field of view, and

the object tracker is further configured to adjust a relative location of the blocking zone in the images so as to maintain a correspondence with the associated image region upon a change of the field of view of the at least one camera.

22. The computer program of claim 18, that further causes the processing device to

track a path of the object.

18. A computer program that, when executed on a processing device, causes the processing device to:

detect an object within a first image from a camera,

identify the object as being non-reportable if the object is located within a defined blocking zone within a field of view of the camera that includes the first image,

detect the object within a second image from the camera, and

identify the object as being reportable if the object in the subsequent image is located beyond the defined blocking zone.

19. The computer program of claim 18, that further causes the processing device to

accept input from a user to create the defined blocking zone.

20. The computer program of claim 19, wherein

accepting input from the user includes identifying coordinates that bound the blocking zone within a reference image corresponding to the field of view of the camera.

21. The computer program of claim 18, that further causes the processing device to

notify a user of the object when the object is identified as being reportable.

23. The computer program of claim 18, that further causes the processing device to

adjust a location of the defined blocking zone relative to the field of view as the field of view changes.

22-1. The computer program of claim 17, that further causes the processing device to

record at least the first image and the second image.