Goalwatcher: a system for the automatic detection of the ball position in soccer games
Andreas Haas, Richard Maierhofer, Rene Sendlhofer, Wolfgang Poelzleitner · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2002
In real-life soccer games it is sometimes very difficult for a referee to decide whether a goal has been achieved or not. This occurs for example, when the ball was caught close to the goal line. Then from the viewing position of the referee it may be entirely impossible to decide what fraction of the ball volume was behind the line. In such cases referee decisions will be rather arbitrary, and subject to scrutiny. We are working on the development of an image analysis system, which uses online monitoring of the goal area to continuously track the position of the ball. Underlying problems are: the estimation of an approximate position to limit the search space; discounting movements of the players that will cause occlusions; the real-time pattern matching which should result in close to frame-rate coordinate output; and geometric design criteria to facilitate calibration and scene-dependent adaptation of the system. In this paper we describe preliminary results of our work, which will be demonstrated using a lab mock-up of the problem. We will pinpoint present problems and a design route to implement a real-world system.