A tracking processing unit performs tracking processing for a plurality of states during a tracking period and, on the basis of a plurality of tracking results obtained from the tracking processing for the plurality of states, tracks the movement of a measurement point during the tracking period. In addition, with regard to a plurality of tracking points that comprise the measurement point and an auxiliary point, the tracking processing unit performs tracking processing for each tracking point during the tracking period and, on the basis of a plurality of tracking results obtained from the plurality of tracking points, tracks the movement of the measurement point during the tracking period.
