Trajectory-Based Ball Detection and Tracking in Broadcast Soccer Video with the Aid of Camera Motion Recovery

This paper presents an enhanced trajectory-based ball detection and tracking algorithm, which acquires 2.5D ball position with the aid of camera motion recovery (CMR). Informally, CMR enhances the algorithm by obtaining better ball candidates and forming longer ball trajectories via computing 2.5D position of the ball. The algorithm in this paper comprises two phases. In the first phase, we achieve CMR by a procedure combining homography and global motion estimation. In the second phase, we employ the trajectory-based procedure to the sequence of transformed frames. The experimental results show that the algorithm presented in this paper achieves higher accuracy in identifying the ball than our previous trajectory-based algorithm. More importantly, the obtained ball position is 2.5D, i.e. the ball projection position.