关键词: 检测, 跟踪, 卡尔曼滤波, 轨迹, 线性插值

Abstract: Due to much noise and frequent occlusion，it is difficult to detect the sole ball in one frame in soccer broadcast video.In this paper，a trajectory based scheme is proposed to achieve robust football detection and tracking.Firstly，multiple ball candidates are detected through visual features.Then each candidate is tracked by Kalman filter in successive frames，which produces many initial trajectories.After trajectory selection，the true ball trajectories are verified，which indirectly gets the ball position in each frame.Further more，combining Kalman filter prediction and linear interpolation，some missing balls can be made up.The experiment shows that the given scheme has high effectiveness and the accuracy is up to 85%.

Key words: detection, tracking, Kalman filtering, trajectory, linear interpolation