Digital camera work for soccer video production with event recognition and accurate ball tracking by switching search method

In this paper, we propose a method of digital zooming by automatically recognizing the soccer game events such as penalty kick and free kick based on player and ball tracking. We also propose an efficient and stable ball tracking method by switching search methods between global search and local search. In the frames where the ball is lost as well as in the first frame, the global search with normalized cross-correlation is performed. Then the local search with particle filter continues the tracking. Once the system has recognized that the local search had failed by receiving a sequence of low probabilities of the ball tracking results, the search method is switched to the global search. We carried out three ball tracking experiments; global search, local search and the proposed switching search method. As a result, the experiments showed the effectiveness of the proposed method.