Method and apparatus to determine golf ball trajectory and flight
View Patent ↗A launch monitor system including a support structure, a first light-reflecting element disposed on this support structure, a lighting unit and an camera unit. A computer receives signals generated by light patterns received by the camera unit and computes a variety of flight characteristics for the object. The system may be moved back and forth to vary the field-of-view of the camera unit. The system also computes and displays object trajectories from the computed flight characteristics which account for the characteristics of the object and the atmospheric conditions.
1. A method of processing images of a golf ball having reflective markers comprising the steps of:
providing first and second cameras;
capturing a first pair of images of the golf ball with the first camera;
capturing a second pair of images of the golf ball with the second camera;
dividing the first and second pair of images into a plurality of pixels;
assigning a color to each pixel, the assigned color being either a first color if the pixel has a brightness above a predetermined threshold level or a second color if the pixel has a brightness below the predetermined threshold level;
connecting adjacent pixels of the first color to form bright areas;
corresponding the bright areas to identify the reflective markers on the golf ball;
calculating the location of the reflective markers by comparing the first pair of images with the second pair of images; and
determining at least one of the transverse velocity and spin rate of the golf ball.
2. The method of claim 1 , wherein the step of capturing the second pair of images comprises delaying the capturing by a predetermined amount of time after the step of capturing the first pair of images.
3. The method of claim 2 , wherein the predetermined amount of time is 800 microseconds.
4. The method of claim 1 , further comprising the step of segmenting the first and second pairs of images into a plurality of distinct segments corresponding to a plurality of bright areas in the first and second images.
5. The method of claim 4 , wherein the step of segmenting the first and second pairs of images further comprises the steps of:
calculating the center of each of the bright areas in the first and second pairs of images;
determining the principal axes of each of the bright areas;
calculating a ratio of the principal axes of each of the bright areas;
eliminating each of the bright areas that has a ratio of the principal axes exceeding a predetermined value.
6. A method of processing images of a golf ball having at least one reflective marker comprising the steps of:
capturing at least one image of the golf ball;
dividing the at least one image into a plurality of pixels;
corresponding an area of the plurality of pixels with the reflective marker on the golf ball;
calculating the location of the reflective marker on the golf ball from the at least one image; and
determining at least one of the transverse velocity and spin rate of the golf ball.
7. The method of claim 6 , wherein the step of capturing at least one image comprises focusing the camera on a predetermined field-of-view.
8. The method of claim 6 , wherein the golf ball has at least six reflective markers.
9. The method of claim 6 , wherein the step of calculating comprises locating bright areas in the at least one image, corresponding the bright areas with the at least one reflective marker, and determining the location of the golf ball.
10. The method of claim 9 , wherein the step of calculating further comprises determining the center of each of the bright areas.
11. A method of processing images of a golf ball having reflective markers comprising the steps of:
providing first and second cameras;
capturing a first pair of images of the golf ball with the first camera;
capturing a second pair of images of the golf ball with the second camera;
dividing the first and second pairs of images into a plurality of pixels;
assigning a color to each pixel, the assigned color being either a first color if the pixel has a brightness above a predetermined brightness threshold level or a second color if the pixel has a brightness below the predetermined brightness threshold level;
connecting adjacent pixels of the first color to form bright areas;
calculating the center of each of the bright areas;
determining the principle axes of each of the bright areas;
calculating a ratio of the principle axes of each of the bright areas;
eliminating each of the bright areas exceeding a predetermined value for the ratio of the principle axes;
corresponding the bright areas to identify the reflective markers on the golf ball; and
calculating the location of the reflective markers from the first and second pairs of images.
12. The method of claim 11 , wherein the step of capturing the second pair of images comprises delaying the capturing by a predetermined amount of time after the step of capturing the first pair of images.
13. The method of claim 11 , further comprises the step of calculating at least one of the transverse velocity and spin rate of the golf ball.
14. The method of claim 11 , further comprises the step of calculating the transverse velocity and spin rate of the golf ball.
15. The method of claim 11 , wherein the predetermined value is 4.
16. The method of claim 15 , wherein the predetermined value is 5.