The present invention concerns a method and associated apparatus for using a trajectory-based technique to detect a moving object in a video sequence, such as the ball in a soccer game. In one embodiment, the method comprises steps of identifying and evaluating sets of connected components in a video frame, filtering the list of connected components by comparing features of the connected components to predetermined criteria, identifying candidate trajectories across multiple frames, evaluating the candidate trajectories to determine a selected trajectory, and processing images in the video sequence based at least in part upon the selected trajectory.