Video scene background maintenance using change detection and classification

• US 6,999,600 B2
• Filed: 01/30/2003
• Issued: 02/14/2006
• Est. Priority Date: 01/30/2003
• Status: Expired due to Term

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: ObjectVideo Incorporated (Alarm.com Holdings, Inc.)
• Inventors: Chosak, Andrew J., Haering, Niels, Zhang, Zhong, Venetianer, Peter L., Lipton, Alan J.
• Primary Examiner(s): PATEL, KANJIBHAI B
• Application Number:
  US10/354,096
• Publication Number:
  US 20040151342A1
• Time in Patent Office: 1,111 Days
• Field of Search: 382/103, 382/104, 382/107, 382/173, 382/232, 382/266, 348/143, 348/149, 348/152, 348/154, 348/171, 348/180, 348/169, 348/208.15, 348/113
• US Class Current: 382/103
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/143 involving probabilistic approaches, e.g. Markov random field [MRF] modelling
• CPC Class Codes: G06T 7/194 involving foreground-background segmentation
• CPC Class Codes: G06T 7/254 involving subtraction of images
• CPC Class Codes: G06V 10/28 Quantising the image, e.g. histogram thresholding for discrimination between background and foreground patterns
• CPC Class Codes: G06V 20/00 Scenes; Scene-specific elements control of digital cameras H04N23/60

Abstract

Video is processed by maintaining a background model for the video, detecting a target in the video, detecting if the target is a stationary target, and classifying the stationary target as an insertion in the background model or a removal from the background model.

Claims

1. A method for processing video, comprising the steps of:

maintaining a background model for said video;

detecting a target in said video;

detecting if said target is a stationary target, wherein detecting if said target is a stationary target comprises the steps of;

determining general motion and size change properties of said target;

determining independent motion properties of said target; and

determining if said target is said stationary target based on said general motion and size change properties and said independent motion properties; and

classifying said stationary target as an insertion in said background model or a removal from said background model.

2. A method as in claim 1, wherein said general motion and size change properties comprise statistical properties of a centroid trajectory of said target and statistical properties of an area of said target.

3. A method as in claim 1, wherein said independent motion properties comprise statistical properties of moving pixels of said target.

4. A method as in claim 1, wherein determining if said target is stationary is further based on aging of said target.

12. A computer system comprising a computer-readable medium having software to operate a computer in accordance with the method of claim 1.

13. A computer-readable medium having software to operate a computer in accordance with the method of claim 1.

5. Method for processing video, comprising the steps of:

maintaining a background model for said video;

detecting a target in said video;

detecting if said target is a stationary target; and

classifying said stationary target as an insertion in said background model or a removal from said background model, wherein classifying said stationary target comprises the steps of;

determining an edge strength in said background model along a boundary of said stationary target;

determining an edge strength in a current frame of video sequence along said boundary of said stationary target; and

determining if said stationary target is said insertion or said removal based on said edge strength in said background model and said edge strength in said current frame.

6. A method as in claim 5, wherein determining said edge strength in said background model is based on a centroid pixel of said stationary target and perimeter pixels along said boundary of said stationary target.

7. A method as in claim 5, wherein determining said edge strength in said current frame is based on a centroid pixel of said stationary target and perimeter pixels along said boundary of said stationary target.

8. A computer system comprising a computer-readable medium having software to operate a computer in accordance with the method of claim 5.

9. A computer-readable medium having software to operate a computer in accordance with the method of claim 5.

10. A method for processing video, comprising the steps of:

maintaining a background model for said video;

detecting a target in said video;

detecting if said target is a stationary target; and

classifying said stationary target as an insertion in said background model or a removal from said background model, or as being unidentifiable as said insertion or said removal.

11. A method for processing video, comprising the steps of:

maintaining a background model for said video;

detecting a target in said video;

detecting if said target is a stationary target; and

classifying said stationary target as an insertion in said background model or a removal from said background model; and

determining if said target was previously detected as a stationary target.

14. A computer system for processing video, comprising:

a background model of said video;

a background model-based pixel classification to produce a change mask and imagery based on said video and said background model;

a background model update to update said background model based on said change mask and said imagery;

a motion-based pixel classification to produce a motion mask based on said video;

a blob generation to produce at least one blob based on said change mask and said motion mask;

a blob tracking to produce at least one target based on said blobs;

a stationary target detection and classification to produce a stationary target description based on each target, said stationary target description to identify each said target as an insertion in said background model or a removal from said background model; and

a background model local update to update said background model based on each said stationary target description.

15. A computer system as in claim 14, wherein said stationary target descriptions further identify each of said targets as an insertion in said background model, a removal from said background model, or as being unidentifiable as said insertion or said removal.

16. A computer system as in claim 14, further comprising:

a stationary target monitor to produce a target reactivation for said blob tracking based each said stationary target description.

17. An apparatus for processing video, comprising:

means for maintaining a background model for said video;

means for detecting a target in said video;

means for detecting if said target is a stationary target, wherein the means for detecting if said target is a stationary target comprises;

means for determining general motion and size change properties of said target;

means for determining independent motion properties of said target; and

means for determining if said target is said stationary target based on said general motion and size change properties and said independent motion properties; and

means for classifying said stationary target as an insertion in said background model or a removal from said background model.

18. An apparatus to process video adapted to perform operations comprising a method of:

maintaining a background model for said video;

detecting a target in said video;

detecting if said target is a stationary target, wherein detecting if said target is a stationary target comprises the steps of;

determining general motion and size change properties of said target;

determining independent motion Properties of said target; and

determining if said target is said stationary target based on said general motion and size change properties and said independent motion properties; and

classifying said stationary target as an insertion in said background model or a removal from said background model.

19. The apparatus of claim 18, wherein said apparatus comprises application-specific hardware to emulate a computer anchor software, said hardware adapted to perform said maintaining, said detecting a target in said video, said detecting if said target is a stationary target, and said classifying.

20. An apparatus for processing video, comprising:

means for maintaining a background model for said video;

means for detecting a target in said video;

means for detecting if said target is a stationary target; and

means for classifying said stationary target as an insertion in said background model or a removal from said background model, wherein said means for classifying said stationary target comprises;

means for determining an edge strength in said background model along a boundary of said stationary target;

means for determining an edge strength in a current frame of video sequence along said boundary of said stationary target; and

means for determining if said stationary target is said insertion or said removal based on said edge strength in said background model and said edge strength in said current frame.

21. An apparatus to process video adapted to perform operations comprising a method of:

maintaining a background model for said video;

detecting a target in said video;

detecting if said target is a stationary target; and

classifying said stationary target as an insertion in said background model or a removal from said background model, wherein classifying said stationary target comprises the steps of;

determining an edge strength in said background model along a boundary of said stationary target;

determining an edge strength in a current frame of video sequence along said boundary of said stationary target; and

determining if said stationary target is said insertion or said removal based on said edge strength in said background model and said edge strength in said current frame.

22. The apparatus of claim 21, wherein said apparatus comprises application-specific hardware to emulate a computer and/or software, said hardware adapted to perform said maintaining, said detecting a target in said video, said detecting if said target is a stationary target, and said classifying.