Group tracking in motion capture

• US 8,224,025 B2
• Filed: 12/21/2006
• Issued: 07/17/2012
• Est. Priority Date: 12/23/2005
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Pictures Entertainment Incorporated (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Pictures Entertainment Incorporated (Sony Group Corp.)
• Inventors: Gordon, Demian
• Primary Examiner(s): Liew, Alex
• Application Number:
  US11/614,867
• Publication Number:
  US 20070146370A1
• Time in Patent Office: 2,035 Days
• Field of Search: 382/103, 382/154, 382115-118
• US Class Current: 382/103
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments

Abstract

Tracking a group of motion capture markers in a sequence of frames, comprising: establishing a group relationship among a plurality of motion capture markers in a current frame; and labeling the plurality of motion capture markers in the current frame using the group relationship.

Claims

1. A computer-implemented method of tracking a group of motion capture markers in a sequence of frames stored on a non-transitory tangible storage medium, the method comprising:

establishing a group relationship among a plurality of motion capture markers in a current frame;

labeling said plurality of motion capture markers in said current frame as a group using said group relationship,

wherein said plurality of motion capture markers in said current frame forms an inherent shape which is used in labeling markers in other frames, and

wherein each motion capture marker in said plurality of motion capture markers is identified by its position in the inherent shape; and

labeling a plurality of unlabeled motion capture markers in a next frame using said group relationship and based on a shape analysis of the group to substantially minimize incorrect marker labeling.

2. The method of claim 1, wherein said next frame is a following frame.

3. The method of claim 1, wherein said next frame is a previous frame.

4. The method of claim 1, wherein said shape analysis includes a stretch analysis.

5. The method of claim 4, wherein said stretch analysis includes FACS stretch.

6. The method of claim 4, wherein said plurality of motion capture markers are labeled such that deviance from a group stretch is minimized.

7. The method of claim 6, wherein said group stretch is defined in another frame.

8. The method of claim 1, further comprising

omitting labeling a plurality of motion capture markers in an intervening frame disposed between said current frame and said next frame.

9. The method of claim 1, wherein a particular marker is not labeled when multiple labeling solutions for said particular marker exist.

10. The method of claim 1, wherein said group relationship includes

at least a predetermined number of motion capture markers.

11. The method of claim 10, wherein said predetermined number is three.

12. The method of claim 1, wherein when said group relationship includes fewer than a predetermined number of motion capture markers, said group relationship is re-established among a plurality of motion capture markers in a next frame.

13. The method of claim 12, wherein said predetermined number is three.

14. The method of claim 12, wherein another group relationship is used to assist in re-establishing said group relationship in said next frame.

15. The method of claim 1, further comprising

establishing a coordinate system.

16. The method of claim 15, further comprising

configuring said coordinate system for translational invariance with respect to said group relationship.

17. The method of claim 15, further comprising

configuring said coordinate system for rotational invariance with respect to said group relationship.

18. A storage medium configured to store at least one image created using the method of claim 1.

19. The storage medium of claim 18, wherein said at least one image is configured to form a motion picture.

20. A system for tracking a group of motion capture markers in a sequence of frames, comprising:

a reference group module, for generating a reference group of motion capture marker information about the group of motion capture markers; and

a group trajectory labeling module, for generating labeled marker group trajectory data of the group of motion capture markers using said reference group of motion capture marker information,

wherein the labeled marker group trajectory data of motion capture markers is based on a shape analysis of the reference group to substantially minimize incorrect marker labeling,

wherein said group of motion capture markers forms an inherent shape, and

wherein each motion capture marker in said group of motion capture markers is identified by its position in the inherent shape which is used in labeling markers in other frames.

21. The system of claim 20, wherein said reference group module is configured to generate said reference group of motion capture marker information using selected motion capture markers of interest.

22. The system of claim 20, wherein said reference group module is configured to generate said reference group of motion capture marker information using a predetermined reference group.

23. The system of claim 20, wherein said group trajectory labeling module further comprises

a group establishment module for establishing a group relationship among a plurality of motion capture markers in a current frame.

24. The system of claim 20, wherein said group trajectory labeling module further comprises

a shape analysis module for generating shape analysis information to aid in said generating labeled marker group trajectory data.

25. The system of claim 24, wherein said group trajectory labeling module further comprises

a stretch analysis module for aiding in said generating shape analysis information.

26. A storage medium configured to store at least one image created using the system of claim 20.

27. The storage medium of claim 26, wherein said at least one image is configured to form a motion picture.

28. An apparatus tracking a group of motion capture markers in a sequence of frames, comprising:

means for establishing a group relationship among a plurality of motion capture markers in a current frame;

means for labeling said plurality of motion capture markers in said current frame as a group using said group relationship,

wherein said plurality of motion capture markers in the current frame forms an inherent shape which is used in labeling markers in other frames, and

wherein each motion capture marker in said plurality of motion capture markers is identified by its position in the inherent shape; and

means for labeling a plurality of unlabeled motion capture markers in a next frame using said group relationship and based on a shape analysis of the group to substantially minimize incorrect marker labeling.

29. The apparatus of claim 28, further comprising

means for omitting labeling a plurality of motion capture markers in an intervening frame disposed between said current frame and said next frame.

30. The apparatus of claim 28, further comprising

means for establishing a coordinate system.

31. The apparatus of claim 30, further comprising

means for configuring said coordinate system for translational invariance with respect to said group relationship.

32. The apparatus of claim 30, further comprising

means for configuring said coordinate system for rotational invariance with respect to said group relationship.

33. A storage medium configured to store at least one image created using the apparatus of claim 28.

34. The storage medium of claim 33, wherein said at least one image is configured to form a motion picture.