1. A composite still image creation device comprising: an acquisition unit which acquires moving image data coded using an interframe predictive coding process, wherein the moving image data includes motion vector data and comprises a plurality of frame images each of which is divided into a plurality of macroblocks, and wherein the motion vector data is included in each of the macroblocks; an extraction unit which extracts the motion vector data in one macroblock in one frame image of the moving image data acquired by the acquisition unit; a selection unit which determines whether the one macroblock is to be selected as a partial image based only on the motion vector data in the one macroblock extracted by the extraction unit and without referring to data in another macroblock, wherein the selection unit further selects, as an additional partial image, at least one macroblock adjacent to the macroblock selected as the partial image irrespective of a value of the motion vector data of the at least one adjacent macroblock; and a combining unit which combines the partial images selected by the selection unit with a still image.