TRAJECTORY DETECTION AND ANALYSIS IN SPORTING EVENTS

• US 20110267461A1
• Filed: 05/02/2011
• Published: 11/03/2011
• Est. Priority Date: 05/03/2010
• Status: Active Grant

• Current Assignee: STATS LLC (Stats Holdings LLC)
• Original Assignee: STATS LLC (Stats Holdings LLC)
• Inventors: Oz, Gal, Tenny, Roy, Shpalensky, Yuri, Birenboim, Michael, Shor, Danielle
• Granted Patent: US 9,058,670 B2
• Time in Patent Office: Days
• US Class Current: 348/142
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30224 Ball; Puck
• CPC Class Codes: G06T 2207/30228 Playing field
• CPC Class Codes: G06T 2207/30241 Trajectory
• CPC Class Codes: G06T 7/215 Motion-based segmentation
• CPC Class Codes: G06T 7/292 Multi-camera tracking

Abstract

It is provided a method for conveying data on a flying object in a scene. The method including capturing video frames of the scene by video cameras to get video frames which include image of the object, identifying the object in captured video frames to get associated object parameters, calculating motion variables, solving motion equations for anticipated object trajectory taking into account certain effects, and conveying data to displaying devices. The certain effects are an effect of object collision with a ground surface, air friction, wind effect, and interaction of a spinning object with air. The method may be applied to a ball in a sporting playing field. The cameras may have variable operating parameters desirable for the calculating the motion variables, which may be determined by camera calibration using captured artifacts of the scene. Shadow of the object may be captured as well and be used to provide data absent due to occluding a of the object from a video camera. Also, the captured frames of a ball may be used to calculate parameters relating to a bat which hits the ball.

Claims

1. A method for conveying data on a flying object in a scene, the method comprising:

(a) capturing a plurality of video frames of the scene by two or more video cameras to get several video frames each including image of the object;

(b) identifying said object in captured video frames to get object parameters associated with said captured video frames;

(c) calculating one or more motion variables of said object using said object parameters;

(d) based on the calculated motion variables, solving motion equations for anticipated object trajectory taking into account at least one effect selected from the group of effects consisting of;

(i) an effect of object collision with a ground surface;

(ii) air friction;

(iii) effect of wind on the object; and

(iv) interaction of a spinning object with air;

and

(e) conveying data related to the anticipated object trajectory as calculated taking into account said at least one effect to one or more devices.

2. The method of claim 1 wherein said scene is a playing field.

3. The method of claim 1 wherein said flying object is a ball.

4. The method of claim 1 wherein the method is used for conveying data on a throwing action associated with said object.

5. The method of claim 1 wherein the effect of object collision with a ground surface is characterized by a predetermined range of a bounciness coefficient, and by one or more parameters associated with a direction of the object after the collision.

6. The method of claim 1 wherein at least one camera has at least one variable operating parameter desirable for said calculating one or more motion variables.

7. The method of claim 6 wherein said at least one camera is calibrated using captured artifacts of the scene.

8. The method of claim 6 wherein said at least one camera is calibrated using data provided by a device measuring parameters associated with the scene.

9. The method of claim 8 wherein at least one of a theodolite or a laser rangefinder measures parameters associated with the scene.

10. The method of claim 1 wherein said anticipated object trajectory complements data absence caused by occluding said object from a video camera of said two or more video cameras.

11. The method of claim 1 wherein the method includes conveying data related to the anticipated object trajectory to a displaying device.

12. A program storage device readable by a computer, tangibly embodying the method of claim 1 executable by the computer to convey data on the flying object.

13. A method for conveying data on a flying object in a scene illuminated by at least one light source providing a shadow of the flying object, the method comprising:

(a) capturing a plurality of video frames of the scene by two or more video cameras to get a plurality of video frames including images of the object and at least one video frame including image of the object shadow;

(b) identifying said object in captured video frames to get object parameters associated with said captured video frames;

(c) identifying said object shadow in at least one captured video frame to get parameters of the object shadow associated with said at least one captured video frame;

(d) calculating one or more motion variables of said object using said object parameters, using said parameters of the object shadow, and using parameters associated with the light source;

(e) based on the calculated motion variables, solving motion equations for anticipated object trajectory; and

(f) conveying data related to the anticipated object trajectory as calculated using said parameters of the object shadow to one or more displaying devices.

14. The method of claim 13 wherein at least one camera has at least one variable operating parameter desirable for said calculating one or more motion variables.

15. The method of claim 14 wherein said at least one camera is calibrated using artifacts of the scene.

16. The method of claim 13 wherein the method complements data absence caused by occluding of said object from a video camera of said two or more video cameras.

17. The method of claim 13 wherein said scene is a playing field.

18. The method of claim 13 wherein said flying object is a ball.

20. The method of claim 18 wherein the method includes:

(i) capturing a plurality of video frames of the playing field to get a first plurality and a second plurality of video frames including images of the first object before the collision and after the collision, respectively;

(ii) identifying said first object in captured video frames to get parameters of the first object before the collision and after the collision;

(iii) calculating one or more motion variables of said first object before and after the collision using its respective parameters;

(iv) calculating motion variables of said second object in relation to the collision based on the calculated motion variables of the first object.

21. The method of claim 18 wherein parameters of the second object are used in conjunction with the calculated motion variables of the first object before the collision to calculate additional parameters of said second object related to the collision.

22. The method of claim 18 wherein the method includes calculating position of said second object in the collision, velocity of said second object in relation to the collision, and time of the collision.

19. A method for conveying data relating to a collision occurring in a playing field between of a first object and a second object, the method comprising:

(a) capturing a plurality of video frames of the playing field by two or more video cameras to get a plurality of video frames including image of the first object;

(b) identifying said first object in captured video frames to obtain parameters of said first object at least before the collision, the parameters being associated with said captured video frames;

(c) calculating one or more motion variables of said first object before the collision using the obtained parameters of said first object;

(d) calculating parameters associated with said second object related to the collision using the calculated motion variables;

and

(e) conveying data related to the calculated parameters to one or more devices.