Detection of stationary objects in video

• US 20070122000A1
• Filed: 11/29/2005
• Published: 05/31/2007
• Est. Priority Date: 11/29/2005
• Status: Abandoned Application

• Current Assignee: ObjectVideo Incorporated (Alarm.com Holdings, Inc.)
• Original Assignee: ObjectVideo Incorporated (Alarm.com Holdings, Inc.)
• Inventors: Haering, Niels, Zhang, Zhong, Yin, Weihong, Lipton, Alan, Chosak, Andrew, Venetianer, Peter
• Application Number:
  US11/288,200
• Publication Number:
  US 20070122000A1
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06V 10/28 Quantising the image, e.g. histogram thresholding for discrimination between background and foreground patterns
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69

Abstract

Video processing to detect a stationary object in a video includes: performing background change detection on the video; performing motion detection on the video; determining stable pixels in the video based on the background change detection; and combining the stable pixels to identify at least one stationary object in the video.

Claims

1. A computer-readable medium comprising software for video processing, which when executed by a computer system, cause the computer system to perform operations comprising a method of:

performing background change detection on a video;

performing motion detection on the video;

determining stable pixels in the video based on the background change detection;

combining the stable pixels to identify at least one stationary object in the video.

2. A computer-readable medium as in claim 1, wherein determining stable pixels comprises:

updating temporal histories of intensities of pixels in the video based on the background change detection;

detecting changes in the temporal history of pixel intensity to obtain detected changes;

determining pixel statistics for pixels in the video based on the detected changes;

identifying pixels as candidate stable pixels based on the pixel statistics; and

identifying candidate stable pixels as stable pixels based on the temporal histories.

3. A computer-readable medium as in claim 1, wherein the method is performed on spatially sub-sampled images of the video.

4. A computer-readable medium as in claim 1, wherein the method is performed on temporally sub-sampled images of the video.

5. A computer-readable medium as in claim 1, wherein combining the stable pixels is based on a dual stability threshold.

6. A computer-readable medium as in claim 1, the method further comprising categorizing the stationary object as an inserted stationary object or a removed stationary object.

7. A computer-readable medium as in claim 1, wherein the stationary object is included in the background of the video.

8. A computer-readable medium as in claim 1, the method further comprising detecting activity based on the stationary object.

9. A computer-readable medium as in claim 1, the method further comprising:

detecting an object based on the background change detection and the motion detection to obtain a detected object;

tracking the detected object to obtain a tracked object; and

classifying the object to obtain a classified object.

10. A computer-readable medium as in claim 9, wherein if the tracked object overlaps the stationary object, the stationary object inherits the classification of the tracked object.

11. A computer-readable medium as in claim 1, wherein the background change detection generates a foreground mask, wherein the motion detection generates a non-moving pixels mask, and wherein determining stable pixels comprises:

combining the foreground mask and the non-moving pixels mask to obtain a mask having non-moving foreground pixels, wherein the stable pixels are determined based on the mask having non-moving foreground pixels.

12. A computer-readable medium as in claim 11, wherein the foreground mask and the non-moving pixels mask are combined based on a Boolean AND operation.

13. A computer system to perform operations in accordance with the software of the computer-readable medium of claim 1.

14. An apparatus to perform a video processing method, the method comprising:

performing background change detection on a video;

performing motion detection on the video;

determining stable pixels in the video based on the background change detection;

combining the stable pixels to identify at least one stationary object in the video.

15. An apparatus as in claim 14, wherein determining stable pixels comprises:

updating temporal histories of intensities of pixels in the video based on the background change detection;

detecting changes in the temporal history of pixel intensity to obtain detected changes;

determining pixel statistics for pixels in the video based on the detected changes;

identifying pixels as candidate stable pixels based on the pixel statistics; and

identifying candidate stable pixels as stable pixels based on the temporal histories.

16. An apparatus as in claim 14, wherein the method is performed on spatially sub-sampled images of the video.

17. An apparatus as in claim 14, wherein the method is performed on temporally sub-sampled images of the video.

18. An apparatus as in claim 14, wherein combining the stable pixels is based on a dual stability threshold.

19. An apparatus as in claim 14, the method further comprising categorizing the stationary object as an inserted stationary object or a removed stationary object.

20. An apparatus as in claim 14, wherein the stationary object is included in the background of the video.

21. An apparatus as in claim 14, the method further comprising:

detecting activity based on the stationary object.

22. An apparatus as in claim 14, the method further comprising:

detecting an object based on the background change detection and the motion detection to obtain a detected object;

tracking the detected object to obtain a tracked object; and

classifying the object to obtain a classified object.

23. An apparatus as in claim 22, wherein if the tracked object overlaps the stationary object, the stationary object inherits the classification of the tracked object.

24. An apparatus as in claim 14, wherein the background change detection generates a foreground mask, wherein the motion detection generates a non-moving pixels mask, and wherein determining stable pixels comprises:

combining the foreground mask and the non-moving pixels mask to obtain a mask having non-moving foreground pixels, wherein the stable pixels are determined based on the mask having non-moving foreground pixels.

25. An apparatus as in claim 24, wherein the foreground mask and the non-moving pixels mask are combined based on a Boolean AND operation.

26. An apparatus as in claim 14, wherein the apparatus comprises application-specific hardware to perform the video processing method.

27. A video camera comprising the apparatus of claim 14.

28. A digital video recorder comprising the apparatus of claim 14.

29. A router comprising the apparatus of claim 14.