Patent ID: 7092547

Claim:
A method of processing image data, comprising: determining a curved surface defined by a temporal transition of an object region in video data over a plurality of frames, the transition of the object being presented by a spatiotemporal locator specifying trajectories of representative points of an approximate figure representing the object, the spatiotemporal locator being defined for each object and including identification information of the object, an object appearing time representing a time at which the object appears, an object disappearing time representing a time at which the object disappears, a shape flag representing a shape of the approximate figure, and trajectory data representing the trajectories of the representative points, the trajectory data for each representative point including a number of knots of a function approximating the trajectory of the representative point, a first knot appearing time representing a time of a first knot of the function, and polynomial data representing parts of function between two knots, each polynomial data including a knot time representing an end knot time, a polynomial order representing an order of the parts of function, and polynomial coefficient data representing coefficients of a polynomial representing the function; determining a reference trajectory which is at least a trajectory of a point which is different from the temporal transition of the object region; determining when the reference trajectory crosses the curved surface; and outputting an indication of whether the reference trajectory crosses the curved surface.