The invention discloses a method for acquiring three-dimensional trajectories of balls. The method comprises the steps: acquiring video images, namely acquiring single video
stream image information of ball motion through camera and television video signals; constructing a three-dimensional model, namely constructing a projection
transformation matrix between a match standard field model and the video images by taking a ball match standard field as a target; acquiring the three-dimensional information, namely acquiring the three-dimensional information of a moving ball in the standard field model in the match video images through the projection
transformation matrix. According to the method, information on the speed, arc and placement of the ball can be acquired from single video streams; according to the method, the three-dimensional trajectories of the balls can be acquired, and technical and tactical parameters, such as stroking speed, bending
radian of a three-dimensional trajectory, over-net height,
flight distance and placement, of a table
tennis ball can be further calculated; analysis on technical and tactical information can help coaches and
athletes to improve the technical and tactical level, and thus, the comprehensive competitiveness of ball match events of our country is improved.