METHODS AND SYSTEMS OF DETERMINING COSTS FOR OBJECT TRACKING IN VIDEO ANALYTICS

• US 20170345179A1
• Filed: 08/05/2016
• Published: 11/30/2017
• Est. Priority Date: 05/24/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gao, Jinglun, Bi, Ning, Chen, Ying, Wang, Lei
• Granted Patent: US 10,026,193 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06T 2207/10004 Still image; Photographic image
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 7/251 involving models
• CPC Class Codes: G06T 7/277 involving stochastic approaches, e.g. using Kalman filters
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes

Abstract

Techniques and systems are provided for processing video data. For example, techniques and systems are provided for determining costs for blob trackers and blobs. A blob can be detected in a video frame. The blob includes pixels of at least a portion of a foreground object. A physical distance between a blob tracker and the blob can be determined. A size ratio between the blob tracker and the blob can also be determined. A cost between the blob tracker and the blob can then be determined using the physical distance and the size ratio. In some cases, a spatial relationship between the blob tracker and the blob is determined, in which case the physical distance can be determined based on the spatial relationship. Blob trackers can be associated with blobs based on the determined costs between the blob trackers and the blobs.

Claims

1. A method of determining costs between blob trackers and blobs, the method comprising:

detecting a blob in a video frame, wherein the blob includes pixels of at least a portion of a foreground object;

determining a physical distance between a blob tracker and the blob;

determining a size ratio between the blob tracker and the blob; and

determining a cost between the blob tracker and the blob using the physical distance and the size ratio, wherein the cost between the blob tracker and the blob is used to associate one or more of the blob trackers with one or more of the blobs.

2. The method of claim 1, further comprising associating the blob tracker with the blob based on the determined cost.

3. The method of claim 1, further comprising:

determining a spatial relationship between the blob tracker and the blob, the spatial relationship including an amount of overlap between the blob tracker and the blob, wherein the physical distance is determined based on the spatial relationship.

4. The method of claim 3, wherein determining the spatial relationship between the blob tracker and the blob includes:

determining an amount of overlap between the blob tracker and the blob in a first dimension; and

determining an amount of overlap between the blob tracker and the blob in a second dimension.

5. The method of claim 4, wherein determining the physical distance between the blob tracker and the blob includes:

determining a negative distance between the blob tracker and the blob when overlap is determined between the blob tracker and the blob in the first dimension and in the second dimension.

6. The method of claim 5, wherein the negative distance includes a ratio between an area of intersection of the blob tracker and the blob and an area of union of the blob tracker and the blob.

7. The method of claim 4, wherein determining the physical distance between the blob tracker and the blob includes:

determining a minimum distance in the first dimension between the blob tracker and the blob, wherein the minimum distance in the first dimension is determined when overlap is determined between the blob tracker and the blob in the second dimension and no overlap is determined between the blob tracker and the blob in the first dimension.

8. The method of claim 4, wherein determining the physical distance between the blob tracker and the blob includes:

determining a minimum distance in the second dimension between the blob tracker and the blob, wherein the minimum distance in the second dimension is determined when overlap is determined between the blob tracker and the blob in the first dimension and no overlap is determined between the blob tracker and the blob in the second dimension.

9. The method of claim 1, wherein determining the cost for the blob tracker and the blob includes weighting the physical distance by the size ratio.

10. The method of claim 1, wherein the size ratio includes a ratio between an area of a tracker box associated with the blob tracker and an area of a blob box associated with the blob.

11. An apparatus comprising:

a memory configured to store video data; and

a processor configured to;

detect a blob in a video frame, wherein the blob includes pixels of at least a portion of a foreground object;

determine a physical distance between a blob tracker and the blob;

determine a size ratio between the blob tracker and the blob; and

determine a cost between the blob tracker and the blob using the physical distance and the size ratio, wherein the cost between the blob tracker and the blob is used to associate one or more blob trackers with one or more blobs.

12. The apparatus of claim 11, wherein the processor is further configured to associate the blob tracker with the blob based on the determined cost.

13. The apparatus of claim 11, wherein the processor is further configured to:

determine a spatial relationship between the blob tracker and the blob, the spatial relationship including an amount of overlap between the blob tracker and the blob, wherein the physical distance is determined based on the spatial relationship.

14. The apparatus of claim 13, wherein determining the spatial relationship between the blob tracker and the blob includes:

determining an amount of overlap between the blob tracker and the blob in a first dimension; and

determining an amount of overlap between the blob tracker and the blob in a second dimension.

15. The apparatus of claim 14, wherein determining the physical distance between the blob tracker and the blob includes:

determining a negative distance between the blob tracker and the blob when overlap is determined between the blob tracker and the blob in the first dimension and in the second dimension.

16. The apparatus of claim 15, wherein the negative distance includes a ratio between an area of intersection of the blob tracker and the blob and an area of union of the blob tracker and the blob.

17. The apparatus of claim 14, wherein determining the physical distance between the blob tracker and the blob includes:

determining a minimum distance in the first dimension between the blob tracker and the blob, wherein the minimum distance in the first dimension is determined when overlap is determined between the blob tracker and the blob in the second dimension and no overlap is determined between the blob tracker and the blob in the first dimension.

18. The apparatus of claim 14, wherein determining the physical distance between the blob tracker and the blob includes:

determining a minimum distance in the second dimension between the blob tracker and the blob, wherein the minimum distance in the second dimension is determined when overlap is determined between the blob tracker and the blob in the first dimension and no overlap is determined between the blob tracker and the blob in the second dimension.

19. The apparatus of claim 11, wherein determining the cost for the blob tracker and the blob includes weighting the physical distance by the size ratio.

20. The apparatus of claim 11, wherein the size ratio includes a ratio between an area of a tracker box associated with the blob tracker and an area of a blob box associated with the blob.

21. The apparatus of claim 11, further comprising a camera configured to capture the video data.

22. The apparatus of claim 11, further comprising a network interface configured to communicate the video data.

23. The apparatus of claim 22, wherein the network interface is configured to communicate Internet Protocol (IP) based data.

24. A computer readable medium having stored thereon instructions that when executed by a processor perform a method, including:

detecting a blob in a video frame, wherein the blob includes pixels of at least a portion of a foreground object;

determining a physical distance between a blob tracker and the blob;

determining a size ratio between the blob tracker and the blob; and

determining a cost between the blob tracker and the blob using the physical distance and the size ratio, wherein the cost between the blob tracker and the blob is used to associate one or more blob trackers with one or more blobs.

25. The computer readable medium of claim 24, further comprising associating the blob tracker with the blob based on the determined cost.

26. The computer readable medium of claim 24, further comprising:

determining a spatial relationship between the blob tracker and the blob, the spatial relationship including an amount of overlap between the blob tracker and the blob, wherein the physical distance is determined based on the spatial relationship.

27. The computer readable medium of claim 26, wherein determining the spatial relationship between the blob tracker and the blob includes:

determining an amount of overlap between the blob tracker and the blob in a first dimension; and

determining an amount of overlap between the blob tracker and the blob in a second dimension.

28. The computer readable medium of claim 27, wherein determining the physical distance between the blob tracker and the blob includes:

determining a negative distance between the blob tracker and the blob when overlap is determined between the blob tracker and the blob in the first dimension and in the second dimension, wherein the negative distance includes a ratio between an area of intersection of the blob tracker and the blob and an area of union of the blob tracker and the blob.

29. The computer readable medium of claim 27, wherein determining the physical distance between the blob tracker and the blob includes:

determining a minimum distance in the first dimension between the blob tracker and the blob, wherein the minimum distance in the first dimension is determined when overlap is determined between the blob tracker and the blob in the second dimension and no overlap is determined between the blob tracker and the blob in the first dimension;

or

determining a minimum distance in the second dimension between the blob tracker and the blob, wherein the minimum distance in the second dimension is determined when overlap is determined between the blob tracker and the blob in the first dimension and no overlap is determined between the blob tracker and the blob in the second dimension.

30. The computer readable medium of claim 24, wherein determining the cost for the blob tracker and the blob includes weighting the physical distance by the size ratio, and wherein the size ratio includes a ratio between an area of a tracker box associated with the blob tracker and an area of a blob box associated with the blob.