Extracting Key Sub-trajectory Features for Supervised Tactic Detection in Sports Video
Yi Zhang, Changsheng Xu, Hanqing Lu · 2010
Tactic analysis is receiving more attention in sports video analysis for its assistance to coaches and players. This paper proposes an efficient key sub-trajectory feature representation of ball trajectory for tactic analysis. Ball trajectories are modeled with the generalized suffix tree where frequent sub-trajectory patterns are searched for. Key sub-trajectory patterns are extracted by further filtering these frequent sub-trajectory patterns. Instead of directly using individual sub-trajectories as features to train tactic detectors, we take key sub-trajectory patterns as a whole. Key sub-trajectory feature representation effectively removes noise, reduces the dimension of features, and improves the performance of supervised learning to detect tactics.