System and method for determining impact characteristics of sports ball striking element

1. A computer-implemented method for determining impact characteristics of a ball striking element with a sports ball, comprising:

selecting a first image from a sequence of images received from an imager captured within a predetermined time span of an impact of the sports ball with the ball striking element;

determining an outline of a portion of the ball striking element in the first image based on computer vision techniques applied to the first image;

identifying a fix line on the ball striking element based on the determined outline of the ball striking element;

determining an impact time of the impact of the sports ball with the ball striking element;

determining an angle of the fix line at the impact time from the sequence of images;

determining an impact characteristic of the ball striking element with the sports ball based on the angle of the fix line at the impact time; and

outputting, to a display, the impact characteristic.

2. The computer-implemented method of claim 1 , further comprising generating a reference image by subtracting an estimated background portion from the first image, wherein the outline of a portion of the ball striking element is determined based on the reference image.

3. The computer-implemented method of claim 1 , further comprising comparing the fix line with known geometric properties of the ball striking element to determine a three-dimensional angle of the ball striking element at the impact time.

4. The computer-implemented method of claim 3 , wherein the ball striking element is a golf club comprising a club face and wherein the fix line is an axis of a shaft of the golf club, further comprising:

determining an orientation of the club face during the predetermined time span; and

determining based on the axis and a known angular relationship between the club face and the club shaft, a three-dimensional orientation of the club shaft at the impact time.

5. The computer-implemented method of claim 1 , further comprising:

determining a deflection of the fix line, with respect to known geometric properties of the ball striking element, in at least one of the first image and a second image from the sequence of images; and

determining a flexing of the ball striking element during the predetermined time span.

6. The computer-implemented method of claim 1 , further comprising:

determining a deviation, with respect to the known geometric properties of the ball striking element, of the fix line in the first image and a second image from the sequence of images; and

determining whether the ball striking element contacted a ground surface based on the determined deviation.

7. The computer-implemented method of claim 6 , further comprising determining when the ball striking element contacted the ground surface relative to the impact time.

8. The computer-implemented method of claim 1 , wherein, when the sport ball is stationary prior to impact, a position of the sports ball at the impact time is predetermined.

9. The computer-implemented method of claim 1 , wherein, when the sports ball is stationary prior to impact, a distance from the sports ball to the imager at the impact time is determined based on a size of the sports ball in an image captured prior to the impact time.

10. The computer-implemented method of claim 1 , wherein the first image and a second image from the sequence of images are captured immediately prior to the impact time.

11. The computer-implemented method of claim 1 , wherein the first image and a second image from the sequence of images are captured immediately after the impact time.

12. The computer-implemented method of claim 1 , wherein the first image is captured immediately prior to the impact time and a second image from the sequence of images is captured immediately after the impact time.

13. The computer-implemented method of claim 1 , further comprising:

synchronizing the imager with a microphone;

receiving, from the microphone, a signal during the predetermined time span; and

determining the impact time based on a sound of the impact detected in the microphone signal.

14. The computer-implemented method of claim 1 , further comprising:

synchronizing the imager with a radar; and

receiving from radar data indicating a velocity of at least one of the ball striking element and the sports ball during the predetermined time span, wherein the impact time is determined based on a timing of a discontinuity in the velocity of the one of the ball striking element and the sports ball over the predetermined time span.

15. The computer-implemented method of claim 1 , further comprising determining based on the first image and a second image from the sequence of images a three dimensional path of the ball striking element during the predetermined time span.

16. A computer-implemented method for determining impact characteristics of a ball striking element with a sports ball, comprising:

selecting a first image from a sequence of images received from an imager captured within a predetermined time span of an impact of the sports ball with the ball striking element;

determining an outline of a portion of the ball striking element in the first image based on computer vision techniques applied to the first image;

identifying a fix point on the ball striking element based on the determined outline of the ball striking element;

determining an impact time of the impact of the sports ball with the ball striking element; and

determining a location of the fix point relative to the sports ball at the impact time based on a location of the fix point in the first image and a second image from the sequence of images;

determining an impact characteristic of the ball striking element with the sports ball based on the location of the fix point relative to the sports ball at the impact time; and

outputting the impact characteristic to a display.

17. The computer-implemented method of claim 16 , further comprising determining based on data from a radar synchronized with the imager a velocity of at least one of the ball striking element and the sports ball during the predetermined time span, wherein the impact time is determined based on a timing of a discontinuity in the velocity of the one of the ball striking element and the sports ball over the predetermined time span.

18. The computer-implemented method of claim 16 , further comprising determining based on a location of the sports ball at the impact time and the location of the fix point at the impact time, a location on the ball striking element at which the sports ball impacted the ball striking element.