WO2007035878A2

WO2007035878A2 - Method and apparatus for determining ball trajectory

Info

Publication number: WO2007035878A2
Application number: PCT/US2006/036845
Authority: WO
Inventors: Jagrut Patel; Sumeet Suri; Sachin Suri
Original assignee: Jagrut Patel; Sumeet Suri; Sachin Suri
Priority date: 2005-09-20
Filing date: 2006-09-20
Publication date: 2007-03-29
Also published as: WO2007035878B1; WO2007035878A3

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.

Description

METHOD AND APPARATUS FOR DETERMINING BALL TRAJECTORY

[0001] The present invention relates generally to object detection and tracking, and more particularly to method and apparatus for determining a ball's trajectory using a high-speed camera. The present 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.

DESCRIPTION OF PRIOR ART

[0002] A ball swing in a game of cricket requires the synchronized action of a specialized in a way that is not particularly intuitive or consistent with the human framework. Focusing on the totality of these various ball movements surpasses the ability of the conscious mind. This requirement for complex and unnatural movements is the principle reason why cricket is considered to be a difficult game to master. Even if one is successful in correctly emulating the precise ball movements of a given professional, it is unclear that the ball movements that are actually produced are correct for a particular person given his or her physical differences.

[0003] Training tools exist that focus on body movements during the ball swing, but none describes or teaches correct ball movement in terms of geometric position of the ball, ball head rotation and three dimensional direction at every point of the ball swing. And none performs computer image recognition of the ball and body position to guide the ball movements, analyze the swing and predict the ball flight.

[0004] Prior inventions have used video recordings of the cricket of various professional players for comparison to a student as though they were magic formulas. In fact, many professionals owe their success more to extensive practice than to excellent techniques. Since tournaments can be seen on national television every weekend, most of the techniques that amateur cricketers would like to learn have become common knowledge and are practiced by most professionals. What is needed is a systematic and effective way to learn and practice these well-known ball movements. These techniques can be interactively taught by a software program that is capable of running on most personal computers equipped with an inexpensive video camera.

[0005] Thus a longstanding and unresolved need exists for an easy to use and inexpensive training system that allows a student to focus precisely on bowler action / position and ball movement with real-time interactive assistance. A further need exists for analysis while practicing back and forth swings with no predetermined timing. The student should be able to spontaneously perform a sequence of swings without prior planning or setup. For a proficient and experienced cricketer, this capability provides effective video feedback during warm-up exercises.

[0006] Previous inventions do not have the benefit of the computer instantaneously recognizing, analyzing, understanding and responding to the motion of the student's balling action, speed and swing/spin and reinforcing the ball and body positions. While simulation based on analyzing the flight of the ball is effective in determining the ball flight, such simulation is ineffective in correcting a student cricketers swing mechanics. Even experience cricket pros have great difficulty in determining and explaining the exact cause of a student cricketers poor swing mechanics. A video camera may be used to analyze the golf swing, but a student has a hard time understanding what a correct swing should look like. Known swing analyzers require the student cricketers to pace their swing to a moving image of a cricket pro. This artificial and unnatural pacing of the student cricketer causes subtle changes in the swing mechanics, which are not repeated when the student cricketer swings at his or her own pace. Thus, there is a longstanding need for an image analysis system that follows the student cricketer rather than the student cricketer following the pace of the swing analyzer.

[0007] In response, various devices, systems, and methods have been developed to alleviate some of the above noted issues video processing and ball tracking in ball games, PCT specification No. WO9805166 discloses a digital motion video processing circuit which can capture, playback and manipulate digital motion video information using the system memory of a computer as a data buffer for holding compressed video data from the circuit. The system memory may be accessed by the circuit over a standard bus. A controller in the circuit directs data flow between input/output ports which transfer a stream of pixel data and to the standard bus. The controller directs data to and from either the standard bus or the input/output port through processing circuitry for compression, decompression, scaling and buffering. The standard bus may be a peripheral component interconnects (PCI) bus. The motion video processing circuit has a data path including pixel data and timing data indicative of a size of an image defined by the pixel data. The timing data is used and/or generated by each component which processes the pixel data, thereby enabling each component to process the pixel data without prior knowledge of the image format. By having processors for handling two compression formats for motion video data connected to this data path, conversion between compression formats, such as between MPEG to Motion JPEG, can be performed.

[0008] An UK specification GB2382033 discloses a method or apparatus that provides a system which is envisaged for use for betting on competitive games comprising means for defining a plurality of game areas, means for associating each game area with a corresponding playing area of a playing field, means for storing game participant information linking a participant with a game area, means for determining a game area in which an event has occurred and means for identifying the game participant associated with the determined game area. The system may be used for betting on football, hockey, ice hockey, basketball, American football, Australian rules football, cricket or baseball. A participant of the game bets on the likelihood of an event occurring in a specific area of the playing field 5 the location of the event in question may be monitored by cameras.

[0009] A PCT specification WO03033081 discloses a cricket wicket monitoring system, which includes a sensor configured for automatically sensing whether or not a cricket bail has been dislodged from a stump. The system also includes an alerting means configured for activation in response to the sensor sensing that a bail has been dislodged from the stump so that activation of the alerting means can be recorded for television coverage of a cricket match and used by a television umpire to adjudicate on "run outs" and "stumpings".

[0010] Another PCT specification WO0141884 A video processing system for use in ball games played within a pitch or the like such as cricket, comprising at least four video cameras arranged in spaced apart relationship at fixed positions around the said area, a video processor and ball tracker to which signals from the cameras are fed, a data store for date which models the said area and includes data representative of characteristic features positioned thereon for use in performance of the game, and a store for data appertaining to rules and/or key events of the ball game played, the video processor being operative to; (a) identify in each frame, from each camera, groups of pixels corresponding to the image of a ball; (b) compute for each frame the 3D position of an image thus identified using ball image data from at least two different cameras; (c) predict a ball flight-path from the said 3D ball position as computed in successive frames; and, (d) map the predicted flight-path on the modelled area so as to identify any interaction with one or more of the said characteristic features, which interaction signifies the occurrence of a key event or a rule infringement. SUMMARY OF THE INVENTION

[0011] In order to solve the aforementioned problems, therefore, it is an object of the present invention to provide an object detection and tracking, and more particularly to method for determining a ball's trajectory using a high-speed camera. Even more particularly, the present invention relates to determining a ball's trajectory using a single camera.

[0012] It is another object of the present invention to provide an apparatus which is most appropriate for implementing the method for determining a ball's trajectory using a high-speed camera.

[0013] It is another object of the present invention to provide a system for capturing the trajectory of a ball in a ball game, within a predetermined area involving an apparatus for determining a ball's trajectory.

[0014] To accomplish the first object, there is provided 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 and display of the video information on a screen

[0015] To accomplish the second object, there is provided 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.

[0016] To accomplish the third object, there is provided 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; 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

[0017] In another object of the present invention there is provided a high-speed camera capture program which is triggered by a manual or an automatic switch.

[0018] In another object of the present invention the motion of the ball is modeled as having an unknown initial position and velocity in the x, y and z directions.

[0019] In another object of the present invention 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. The unknown positions and velocities are determined by solving a set of simultaneous linear equations in the unknowns.

10020] In another object of the present invention 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. [0021] In another object of the present invention the system includes one, two or more cameras with fixed or adjustable frame capture rate and resolution.

[0022] Another exemplary embodiment of the present invention is to provide a visual display of the 3-dimensionally.

[0023] It is another object of the present invention to provide memory means wherein the stored trajectory of the ball is used to facilitate sports training and ball tracking in training / gaming environment.

[0024] It is another object of the present invention is to provide a visual and mathematical comparison of the trajectory of multiple balls simultaneously over a display screen.

[0025] It is another object of the present invention is to provide a visual display and mathematical comparison 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.

[0026] Another exemplary object of the present invention is to display the slow motion of the trajectory of the ball, bowler's action and batsman's action.

[0027] It is another object of the present invention is to provide 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 and further the database is used to generate analysis report and statistics.

[0028] As per another exemplary embodiment of the present invention there is provided a method for capturing the trajectory of a ball in a ball game, within a predetermined area wherein the motion of the ball in each segment can be predicted and can be displayed with the information on a screen.

[0029] It is another object of the present invention is to provide a method which further includes breaking the ball motion into segments free from bounce.

[0030] It is another object of the present invention is to create phantom vertical lines that is representative of a vertical drop line from the ball position using the predicted position of the ball.

[0031] As per another object of the present invention, the method further includes display of a Swing Analysis report on the basis of stored data.

[0032] As per another exemplary embodiment of the present invention a user friendly graphical user interface is provided for a system for capturing the trajectory of a ball in a ball game.

[0033] The above and/or other aspects, features and/or advantages of various embodiments will be further appreciated in view of the following description in conjunction with the accompanying figures. Various embodiments can include and/or exclude different aspects, features and/or advantages. In addition, various embodiments can combine one or more aspect or feature from other embodiments. The descriptions of aspects, features and/or advantages of particular embodiments should not be construed as limiting other embodiments or the claims.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0034] The above objects and advantages of the present invention will become more apparent by describing in detail a preferred embodiment thereof with reference to the attached drawings in which: [0035] Rg. 1 is a schematic diagram showing the position of the camera according to an embodiment of the present invention;

[0036] Fig. 2 is a schematic diagram showing method for calibrating the pitch and yaw of the camera to allow the capture of the trajectory of the ball by a single camera adopted for the present invention;

[0037] Fig 3 shows the basic algorithm of the technology behind the method for an object detection and tracking as per the aspect of the present invention

[0038] Fig. 4 illustrates the algorithm for the processing of the captured image by the camera adopted for the present invention;

[0039] Fig. 5 shows the process of breaking the ball motion into segments free from bounce as per one of the embodiment of the present invention;

[0040] Fig 6A and Fig 6B, shows the different dimensions of the cricket pitch, wicket and the ball used for the game of cricket;

[0041] Fig 7 shows the position of the single camera (view one) as per the embodiment of the present invention;

[0042] Fig 8 shows the position of the single camera (view two) as per the embodiment of the present invention;

[0043] Fig 9 shows the position of the dual cameras (view one) as per the embodiment of the present invention;

[0044] Fig 10 shows the position of the dual cameras (view two) as per the embodiment of the present invention; [0045] Fig 11 shows the infinite horizon view from a single camera as per the as per the embodiment of the present invention;

[0046] Fig 12 shows the capture of the bowlers action as per the embodiment of the present invention;

[0047] Fig 13 shows the algorithm for the video processing of the captured image by the camera adopted for the present invention;

[0048] Fig 14 shows the algorithm for the image processing of the captured image by the camera adopted for the present invention;

[0049] Fig 15 shows the ball trajectory (slow motion) as per the embodiment of the present invention;

[0050] Fig 16 shows the position of the ball trajectory (tracked) as per the embodiment of the present invention;

[0051] Fig 17 shows the position of the ball trajectory (video) per the embodiment of the present invention;

[0052] Fig 18 shows the comparison between some bowled balls in 3- Dimensions as per the embodiment of the present invention;

[0053] Fig 19 shows the 3^rd order polynomial extraction: Ball pitch and stump crossing (1^st view) as per the embodiment of the present invention;

[0054] Fig 20 shows the shows the 3^rd order polynomial extraction: Ball pitch and stump crossing (2^nd view) as per the embodiment of the present invention; and [0055] Fig 21 shows the object tracking from a captured image as per the embodiment of the present invention;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0056] While the present invention may be embodied in many different forms, a number of illustrative embodiments are described herein with the understanding that the present disclosure is to be considered as providing examples of various principles of the invention and such examples are not intended to limit the invention to exemplary or preferred embodiments described herein and/or illustrated herein.

[0057] A typical system for determining the trajectory of a cricket ball involves the use of multiple high frame rate cameras. The method is costly and involves considerable complexity in processing of the multiple images from the different sources. The present patent application discloses a method of tracking an object/ball using a single high frame rate camera on a cricket pitch.

[0058] Preferred embodiments of the present invention will be explained below with reference to the drawings.

[0059] Referring to Fig 1 , which shows the position of the camera for capturing the trajectory of the ball. The camera should be placed in the field such that the line of sight of camera should not obstruct the pitch. A long cable length for cameras (upto 50m) and also no custom calibration is required on field on a periodic basis. The camera used for the purpose for the tracking is having the features like 250/500FPS Full-Frame, Trigger Shutter, High Speed, 640 x 480 Progressive Scan, 1/2" Imaging Format , 9.9um Square Pixel 250 / 500fps Live Snap-Shot Capture, 10 Bits per Pixel etc. [0060] Fig 2 discloses the method for the calibrating of the pitch and the yaw of the camera to allow the capture of the trajectory of the ball by a single camera. The middle stump is adjusted to the middle of the image and cross hair is placed art height of camera on distal end and is in center of the image. The camera is set up at the bowler's end looking down the stump line or at a known angle to the stump line. Also if the camera is facing away from the stump line then calibration may be applied mechanically or may be applied in software. The image captured by the camera is associated with a time stamp and the calibration is such that the very least the top batsman stump is visible. The position of the camera in terms of the back off and height are known with respect to some fixed point.

[0061] Referring to Fig 3, the technology behind the tracking of the ball is to capture the trajectory of the ball by a high speed camera, and with the help of the interface the captured image is taken up for a video pre-processing. The video output is taken up for an image analysis / post processing with smart algorithms and can be visualized on a display device.

[0062] The different camera positions which are identified as the key points for the capture of the trajectory of the ball as per the present invention is shown in Fig 7 and 8. For the capture of the bowlers action and the other parameters such as batsman action, swing analysis, speed of the ball etc one more camera may be used simultaneously with the single camera as shown in Fig 9 and 10.

[0063] As per the first object, the 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. The trapped video information consists of the ball trajectory data along with a time stamp on each frame. Further the trapped video information is processed for the analysis of the speed, X, Y, Z variables, direction, degree of elevation or depression etc. All the data recovered from the video information is stored in a temporary memory for further analysis. [0064] 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.

[0065] The processing of the images from the video information comprising in parts of the steps of but not limited to: 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.

[0066] 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 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; and using parameters for equation of motion to determine position of the ball.

[0067] The computing and the processing of the captured video data part of the ball trajectory and motion parameters are explained in detail below:

[0068] Referring to the Fig. 4, which illustrates the algorithm for the processing of the captured image by the camera. The camera is set up at a point whose dimensions (x, y and z) are known.

■ Assume xo, yo, zo - initial positions of the ball ■ vx, vy, vz - velocities in the different axial directions.

■ ax, ay, az - accelerations in the different axial directions ■ These are the unknowns.

Solution-

Consider a frame at time t1 - The parameters x, y and z at time t1 are:-

■ Xt1 = xo + vx*t1+ax*t1^Λ2/2 ■ yt1 = yo + vy*t1 +ay*t1 ^Λ2/2

■ zt1 = zo + vz^*t1+az*t1^Λ2/2

. Ypixelti /dfp = (yc-(yo + vy*t1 +ay^*t1 ^Λ2/2))/ (zc+ (zo + vz*t1 +az*t1 ^Λ2/2))

■ Linear equation in 6 unknowns - therefore minimum of 6 time snaps for solving for the following α yo, zo, vy, vz, ay, az For the variables xo, vx, ax

■ Using ypt1 and zpt1 from last evaluation

- Xpixelt1/dfp = -(xo + vx*t1+ax^*t1^Λ2/2)/sqrt((yc-ypt1)^Λ2+(zc+zpt1)^Λ2))

■ Linear equation in 3 unknowns

[0069] Referring to the Fig 11 which shows the infinite horizon view from a single camera the calculations for the different variables is as under:

■ Yp1 = dfp(yc-hst)/(zc)

■ Yp2 = dfp*(yc-hst)/(zc+Lp)

■ Thus

Q dfp = (yp1-yp2)/{(yc-hst)*(1/zc-1/(zc+Lp)}

■ dfp is known For any arbitrary point

■ x,y,z

■ Ypixel/dfp = (yc-yp)/(zc+zp)

■ Xpixel/dfp = -xp/sqrt((yc-yp)^Λ2+(zc-κφ)^Λ2))

■ The Ypixel and xpixel are quantized, the general image top level generates an image of the ball moving on the pitch as seen from the bowler's stump.

α The pixel quantization of the image creates issues in identifying x,y,z parameters

First Solution

■ Under condition that the camera is placed at the bowler's end along the line of the stump. The video captured has a poor information on the x-direction.

Second Solution

■ Created programs to simulate the view as seen from 2 angles.

■ Assumed simultaneous timing of frames from both cameras.

■ Assumed knowledge of position and angle of the camera.

■ This gives ~ 5 to 10% error in vx, vy, vz in quiet a few cases

■ Impact of errors in placement of different cameras

■ Impact of timing synchronization between the 2 cameras [0070] The different variable assumed for the calculation of different motion parameters are:

• Field Dimensions: 2256 x 366 x 366 (L x W x H) (here H is for worst case height attainted by the ball) in cm. • Ball Dimensions: 2x Pi x 7.1 (worst case surface area for smallest ball) = 22.4cm2

• Camera Resolution: #.0f.Columns x #.Of.Rows

• Frames/Second:

• Speed of Cricket ball: 160kph to 30kph (fast ball impacts frame rate and slow ball impacts sampling duration)

Frame rate vs. Accuracy

Fast= 160 Kph = 4,444 cm/sec Pitch = 2200 cm SlOW= 50 Kph = 1388 cm/sec Time for Capture

• Time for Fast Bowler (160Kph) = 0.507 sec

• Time for Slow Bowler ( 50 Kph) = 1.661 sec

• Maximum Video Capture required is 2 seconds. • Thus as 200 fps we will have 400 Frames of Captured image.

[0071] As per the second object of the present invention there is provided 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;

[0072] The video processing unit adapted for the processing of the video information comprises of an IP address for the camera; a processor programmed for the configuring the camera; a processor programmed for recognition and execution of the commands initiated from GUI; and a processor programmed for capturing the Frame by Frame or Video (AVI) information and transferring to Image Processing Section.

[0073] An image processing unit adapted for processing of the captured video frame information. The image processing unit comprises of 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.

[0074] A computing unit for computing the video and the image information with respect to the commands initiated at GUI, the unit comprises 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

[0075] The system also comprises of screen for the display of the images.

[0076] As per the third object, there is provided 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; 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

[0077] In case the image of the ball is obstructed by the batsman can was not captured by the camera then the motion of the ball can be estimated and predicted on the basis of the data collected in the previous frames of recording. The prediction is made using a software which calculates / predicts the position vectors x, y and z at a certain period / moment time using the previous data recorded in the memory.

[0078] Similarly the swing of every ball can be calculated / predicted on the basis of the known position vector for a trajectory for a certain period of time. The values can be compared with a set of known values or from the earlier bowled balls.

[0079] The data regarding the tracked ball using the above process is stored in a database sequentially and can be retrieved and compared with the other balls bowled by the same bowler or different bowler on execution of command from the GUI.

[0080] For determining the speed of a ball the time taken by the ball for the first bounce is recorded and thus speed / velocity can be determined by computing the distance covered versus the time taken. As per another embodiment the speed can also be predicted by tracking the ball between two known positions in the pitch.

[0081] All the other data such as batsman action, bowlers action, scores etc can be recorded directly from the video information in the memory. The player's action during the time of bowling or batting can be retrieved on execution of command from the GUI.

[0082] The stored trajectory of a particular tracked ball can also be displayed by breaking the ball motion into segments free from bounce. Also phantom vertical lines can be created (that is representative of a vertical drop line from the ball position using the predicted position of the ball) in the ball trajectory during the display.

[0083] As per another object of the present invention, the method further includes display of a Swing Analysis report on the basis of stored data.

[0084] In case of producing a slow motion for a particular trajectory or any bowler's / batsman action a person skilled in the art can easily understand that it can be done just by adjusting the frame speed for the video captured / produced.

[0085] As per an embodiment of the present invention, the user of the disclosure can figure out the trajectory of the ball in a 3-dimensional space or can identify the position of the ball at a particular instant of time as given in figures 15 to 21. All the data recorded in the memory or database can be retrieved on execution of command from the GUI.

[0086] As per another exemplary embodiment of the present invention a user friendly graphical user interface is provided for a system for capturing the trajectory of a ball in a ball game, 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.

[0087] The above-described embodiments of the invention are intended to be examples of the present invention. Numerous modifications changes and improvements within the scope of the invention will occur to the reader. Those of skill in the art may effect alterations and modifications thereto, without departing from the scope of the invention, which is defined solely by the claims appended hereto.

Claims

Claims:

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 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.

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 any of the preceding claims 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.

9. A method of claim 1 , wherein the processing of the images from the video information comprising in parts of the steps of but not limited to: 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

10. A method of claim 9, wherein the motion of the ball is modeled as having an unknown initial position and velocity in the x, y and z directions.

11. Method of Claim 9, 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.

12. Method of Claim 9, wherein the unknown positions and velocities are determined by solving a set of simultaneous linear equations in the unknowns.

13. 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

14. A method of 13, wherein the relationships between the balls 3-D position and the pixel location / position of the ball in the image is determined by a pinhole camera approximation.

15. A method of 13, 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.

16. A method of claim 13, wherein the determining positions where the ball motion is modeled in more complex ways and more or less unknowns are solved for using the method of solving simultaneous linear equations.

17. A method of claim 13, 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.

18. A method as claimed in any of the preceding claim, includes one, two or more cameras with fixed or adjustable frame capture rate and resolution.

19. A method as claimed in any of the preceding claim, wherein a static image with trajectory line or overlaid ball motion on a single frame is generated and can be displayed on the screen.

20. A method as claimed in any preceding claim, wherein a stored trajectory of the ball is used to facilitate sports training and ball tracking in training / gaming environment. 21 A method as claimed in any preceding claim, 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.

22. A method of claim 21 , further includes rendering the ball in a 3- dimensional which can be visualized on the display screen.

23. A method of claim 21, 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.

24. A method of claim 21 , further includes displaying the slow motion of the trajectory of the ball, bowler's action and batsman's action.

25. 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

26. An apparatus of claim 25, wherein the capturing video information is carried out by at least one high-speed camera.

27. An apparatus in Claim 26, wherein high speed camera system includes one, two or more cameras with fixed or adjustable frame capture rate and resolution.

28. An apparatus in claim 25, wherein the camera capture program is triggered by a manual or an automatic switch.

29. 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; 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

30. A system of claim 29, 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.

31. A system as claimed in any of the preceding claims wherein each image is associated with a time stamp.

32. A system of claim 29, wherein the position of the camera in terms of the back off and height are known with respect to some fixed point.

33. A system of claim 29, wherein the image processing unit adapted for the processing of the images from the video information comprises of: 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

34. A system of claim 33, wherein the unknown positions and velocities are determined by solving a set of simultaneous linear equations in the unknowns.

35. An system of claim 29, 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

36. A system of claim 35, 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.

37. A system of claim 35, 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.

38 A system of claim 35, wherein the determining positions where the ball motion is modeled in more complex ways and more or less unknowns are solved for by using the method of solving simultaneous linear equations

39. A system of claim 35, 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.

40. A system as claimed in any of the preceding claim, includes one, two or more cameras with fixed or adjustable frame capture rate and resolution

41. A system as claimed in any of the preceding claim, 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.

42. A system as claimed in any preceding claim, wherein a stored trajectory of the ball is used to facilitate sports training and ball tracking in training / gaming environment

43. A system as claimed in any preceding claim, 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.

44. A system of claim 35, further includes rendering the ball in a 3- dimensional can be visualized on the display screen.

45. A system of claim 35, further includes identifying other objects with the batsman / bowler.

46. A system of claim 35, 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.

47. A system of claim 35, further includes displaying the slow motion of the trajectory of the ball, bowler's action and batsman action

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

49. A computer readable media of claim 48, wherein the database is used to generate analysis report and statistics.

50. 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 and display of the information on a screen

51. A method of claim 50, wherein the method further includes breaking the ball motion into segments free from bounce.

52. A method of claim 50, 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.

53. A method of claim 50, wherein the method further includes display of a Swing Analysis report on the basis of stored data.

54. 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