WO2007035878B1

WO2007035878B1 - Method and apparatus for determining ball trajectory

Info

Publication number: WO2007035878B1
Application number: PCT/US2006/036845
Authority: WO
Inventors: Jagrut Patel; Sumeet Suri; Sachin Suri
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-09-20
Filing date: 2006-09-20
Publication date: 2007-08-16
Anticipated expiration: 2008-03-20
Also published as: WO2007035878A3; WO2007035878A2

Abstract

The invention relates to a method and apparatus for determining a ball's trajectory using a high-speed camera. The invention further relates to determining a ball's trajectory using a single camera. Even more particularly a method has been devised wherein a stored trajectory of the ball along with different related data is used to facilitate sports training and ball tracking in training / gaming environment.

Claims

AMENDED CLAIMS [received by the International Bureau on 21 May 2007 (21.05.2007)]

1. A method for capturing the trajectory of a ball in a ball game, within a predetermined area comprising the steps of capturing video information and associating the captured video information with the video program; processing the captured video information; storing the video information in a memory; computing the video information to obtain ball trajectory and motion parameters; processing the captured video to generate trajectory overlay video information; wherein the processing the captured vieo to generate trajectory overlay video information comprises: reading of the images captured by camera; detecting the motion of the ball; identifying and labeling the ball; finding the ball: area, XY centroid; extracting the ball image to reference frame; performing frame by frame N^th order polynomial estimation; determining ball pitch and stump crossing; and performing XY to XYZ transformation; and display of the video information on a screen

2. A method of claim 1 , wherein the capturing video information is carried out by at least one high speed camera.

3. A method in Claim 2, wherein the trajectory is captured for the game of cricket.

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4. A method of claim 1 , wherein the processing of the video information comprising the steps of but not limited to: programming the IP address for the Camera, configuring the camera, initiating commands from GUI, capturing the frame by frame or Video (AVI) information and transferring to Image processing section

5 A method of claim 2, wherein the camera is set up at the bowler's end looking down the stump line or at a known angle to the stump line.

6. A method as claimed in claims 1, 2, 3, 4 or 5 wherein each image is associated with a time stamp.

7. A method of claim 4, wherein the position of the camera in terms of the back off and height are known with respect to some fixed point.

8. A method of claim 1 , wherein the motion of the ball is modeled as having an unknown initial position and velocity in the x, y and z directions.

9. Method of Claim 1 , wherein the motion of the ball is modeled as having an unknown acceleration in the x direction, a known acceleration in the y direction equal to the acceleration due to gravity, g and no acceleration in the z direction.

10. Method of Claimi , wherein the unknown positions and velocities are determined by solving a set of simultaneous linear equations in the unknowns.

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11. A method of claim 1 , wherein the computing the video information comprising the steps of; getting x-pixel and y-pixel points for ball; expressing the 3-d position of ball in terms of equations of motion; using pin hole camera approximations to predict X₁Y pixel locations of the ball; using the predicted position to formulate set of simultaneous linear equations; determining parameters for equation of motion by solving equations; and using parameters for equation of motion to determine position of the ball

12. A method of 11 , wherein the relationships between the balls 3-D position and the pixel location / position of the ball in the image is determined by a pin-hole camera approximation.

13. A method of 11 , wherein the parameters for the equation of motion such as the unknown positions, velocities and accelerations and the position of the ball in 3-D space is determined by using the time stamp and calculating for the X, Y and Z positions.

14. A method of claim 11 , wherein the determining positions where the ball motion is modeled using a method that comprises_using at least two cameras to model the ball motion and using a method of solving simultaneous linear equations to solve for unknowns.

15. A method of claim 11 , wherein the method of computing includes downloading data from camera in real time or at fixed interval for further processing over any standard camera interface.

16. A method as claimed in claims 11, 12, 13, 14 or 15, including one, two or more cameras with fixed or adjustable frame capture rate and resolution.

17. A method as claimed in claims 11 , 12, 13, 14 or 15, wherein a static image with trajectory line or overlaid ball motion on a single frame is generated and can be displayed on the screen.

18. A method as claimed in claims 11, 12, 13, 14 or 15, wherein a stored trajectory of the ball is used to facilitate sports training and ball tracking in training / gaming environment.

19. A method as claimed in claims 11 , 12, 13, 14 or 15, wherein the processing of the image information further includes comparing of the trajectory of multiple balls simultaneously and can be visualized on the display screen.

20. A method of claims 11, 12, 13, 14 or 15, further includes rendering the ball in a 3- dimensional which can be visualized on the display screen.

21. A method of claims 11, 12, 13, 14 or 15, further includes finding the velocity of the ball, speed of the ball, comparison of bowled ball with respect to a known good ball and comparison of bowled ball with respect to other bowler.

22. A method of claims 11, 12, 13, 14 or 15, further includes displaying the slow motion of the trajectory of the ball, bowler's action and batsman's action.

23. An apparatus for capturing the trajectory of a ball in a ball game, within a predetermined area comprising: a high end computing platform; high speed camera system; high speed and high performance network hardware and drivers for high speed cameras; a manual or automatic switch to start the camera capture operation; video processing unit adapted for processing of the video information; a memory for the storage and retrieval of data; image processing unit adapted for processing of the captured video frame information; a computing unit for computing the video and the image information with respect to the commands initiated at GUI; and a screen for the display of the images.

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24. An apparatus of claim 23, wherein the capturing video information is carried out by at least one high-speed camera.

25. An apparatus in Claim 24, wherein high speed camera system includes one, two or more cameras with fixed or adjustable frame capture rate and resolution.

26. An apparatus in claim 23, wherein the camera capture program is triggered by a manual or an automatic switch.

27. A system for capturing the trajectory of a ball in a ball game, within a predetermined area comprising: a high end computing platform; high speed camera system; high speed and high performance network hardware and drivers for high speed cameras; a manual or automatic switch to start the camera capture operation; video processing unit adapted for processing of the video information comprising: a processor programmed for the reading the images captured by the camera, a processor programmed for detecting the motion of the ball, a processor programmed for identifying and labeling the ball, a processor programmed for finding the ball: area, XY centroid, extracting the ball image to reference frame, performing frame by frame 3^rd order polynomial estimation, determining ball pitch and stump crossing, performing XY to XYZ transformation; and a memory for the storage and retrieval of data; image processing unit adapted for processing of the captured video frame information; a computing unit for computing the video and the image information with respect to the commands initiated at GUI; and a screen for the display of the images.

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28. A system of claim 27, wherein the camera is set up at the bowler's end looking down the stump line or at a known angle to the stump line.

29. A system as claimed in claims 27 or 28 wherein each image is associated with a time stamp.

30. A system of claim 27, wherein the position of the camera in terms of the back off and height are known with respect to some fixed point.

31. A system of claim 27, wherein the unknown positions and velocities are determined by solving a set of simultaneous linear equations in the unknowns.

32. An system of claim27, wherein computing unit adapted for the computing the video information comprising the steps of: a processor programmed for collecting the x-pixel and y-pixel points for ball; a processor programmed for expressing the 3-d position of ball in terms of equations of motion, using pin hole camera approximations to predict x, y pixel locations of the ball, using the predicted position to formulate set of simultaneous linear equations, determining parameters for equation of motion by solving equations, using parameters for equation of motion to determine position of the ball

33. A system of claim 32, wherein the relationships between the balls 3-D position and the pixel location / position of the ball in the image is determined by a pin-hole camera approximation.

34. A system of claim 32, wherein the parameters for the equation of motion such as the unknown positions, velocities and accelerations and the position of the ball in 3-D space is determined by using the time stamp and calculating for the x, y and z positions.

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35. A system of claim 32, wherein the determining positions where the ball motion is modeled using a method that comprises using at least two cameras to model the ball motion and using a method of solving simultaneous linear equations to solve for unknowns.

36, A system of claim 32, wherein the computing unit further includes a processor adapted for downloading data from camera in real time or at fixed interval for further processing over any standard camera interface.

37. A system as claimed in claims 32, 33, 34, 35 or 36, includes one, two or more cameras with fixed or adjustable frame capture rate and resolution

38. A system as claimed in claims 32, 33, 34, 35 or 36, wherein a static image with trajectory line or overlaid image of ball trajectory on a single frame are generated and can be displayed on the screen.

39. A system as claimed in claims 32, 33, 34, 35 or 36, wherein a stored trajectory of the ball is used to facilitate sports training and ball tracking in training / gaming environment

40. A system as claimed in claims 32, 33, 34, 35 or 36, wherein the processing of the image information further includes comparing of the trajectory of multiple balls simultaneously and can be visualized on the display screen.

41. A system of claim 32, further includes rendering the ball in a 3- dimensional can be visualized on the display screen.

42. A system of claim 32, further includes identifying other objects with the batsman / bowler.

43. A system of claim 32, further includes finding the velocity of the ball, speed of the ball, comparison of bowled ball with respect to a known good ball and comparison of bowled ball with respect to other bowler.

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44. A system of claim 32, further includes displaying the slow motion of the trajectory of the ball, bowler's action and batsman action

45. A computer readable media adapted for capturing the trajectory of a ball, in a ball game, that comprises of: a database which stores all the data appertaining to the trajectory of the ball.

46. A computer readable media of claim 45, wherein the database is used to generate analysis report and statistics.

47. A method for capturing the trajectory of a ball in a ball game, within a predetermined area comprising the steps of capturing video information and associating the captured video information with the selected clip of the video program; processing the captured video information; storing the video information in a memory; computing the video information ; processing the images from the video information; projecting motion of the ball into times for which image is unavailable using the equations of motions and the other parameters therein; predicting the motion of the ball in each segment; an4 display of the information on a screen; and breaking the ball motion into segments free from bounce.

48. A method of claim 47, wherein the method further includes creating a phantom vertical line that is representative of a vertical drop line from the ball position using the predicted position of the ball.

49. A method of claim 47, wherein the method further includes display of a Swing Analysis report on the basis of stored data.

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50. A graphical user interface for a system for capturing the trajectory of a ball in a ball game, preferably cricket, within a predetermined area comprising: a single window interface including a plurality of alternatively selectable interfaces wherein a first of the plurality of selectable interfaces is an interface for making capturing commands available to a user for receiving motion video information to be edited, and wherein a second of the plurality of selectable interfaces is an interface for making editing commands available to a user for editing the received motion video information, and wherein a third of the plurality of selectable interfaces is an interface for making playback commands available to a user for outputting the edited motion video information to an external device.

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