Abstract: This paper explores the question of detecting and tracking multiple athletes in a short track speed skating video and reconstructing their trajectories. The current technology is difficult to ensure that each target is completely tracked and its trajectory is recovered in a complex motion video with frequent blocking and interlaced positions. We propose a complete algorithm flow to quickly and accurately detect and track athletes. Further, a trajectory reconstruction algorithm based on cubic B-spline curve is proposed. Using the nonuniformity and continuity of the B-spline curve, this algorithm can completely match the smooth motion trajectory of each target in the absence of partial tracking results. Experiments show that this algorithm can detect and track multiple athletes and rebuild their trajectories, and the results obtained can be further used in the actual technical and tactical analysis.

Key words: short track speed skating, detecting and tracking, B-spline curve, trajectory reconstruction