1. An information processing device configured to track the image of a tracking point which is a tracking target within a moving image wherein contents, of a plurality of images which are continuous temporally, are discontinuous temporally, said information processing device comprising: block matching means configured to perform block matching regarding some images of said moving image, wherein an image to be processed and an image which is temporally prior to said image to be processed are compared to determine the position of said tracking point within said image to be processed; interpolation means configured to perform interpolation processing wherein the position of said tracking point within an image which is not subjected to said block matching by said block matching means, which is an image before or after said image to be processed within said moving image, having content at the same point-in-time as that of said image to be processed, is determined as the position of said tracking point within said image to be processed; and motion vector calculating means configured to obtain the motion vector of said tracking point from an image which is temporally prior to said image to be processed to said image to be processed based on the position of said tracking point within said image to be processed determined by said block matching means or said interpolation means.