The present disclosure relates to a method, system and medium for determining a ball trajectory and bounce position.
Officiating referees, judges and umpires in many sports including tennis, cricket and baseball, for example, use technology to assist in determining ball bounce positions or in making boundary crossing judgments according to the rules of the sport. This is also of interest in other sports such as baseball or golf, for example, to measure the flight path of the pitched or struck ball. Such measurements can provide indications of the performance of players and equipment.
The state of the art includes methods to track a moving ball by electronic cameras. These methods are commonly found in video tracking, for example, using multiple synchronized cameras that view a moving ball from multiple perspectives, with each camera recording images of the moving ball. Estimates can be made of the ball position in the image frames. The position of the ball can be calculated through triangulation. In order to be successful, the images typically rely on one or more of the following processes: (a) “finding” the ball in the image frame, usually by means of edge detection or correlation techniques, and estimating the position of the centroid of the object (i.e. the ball image), and (b) “normalization” of the image to intensity scales that allow the rules to “find” the ball in the image to work successfully.