1. A coding method for motion-image data in which each of image frames, arranged along a time axis so as to constitute motion-image data, is sequentially and individually compressed along a time axis, the coding method comprising the steps of: setting a virtual image frame comprised of a plurality of sub-regions, as an image frame to be coded: allocating one selected from at least one of a plurality of sub-images obtained by dividing an image frame to be coded out of the image frames constituting the motion-image data, and a clipped image obtained from another information source different from the motion-image data, to each of the plurality of sub-regions constituting the virtual image frame; and individually compressing each of the images allocated to the plurality of sub-regions constituting the virtual image frame, according to a coding level set for each of the plurality of sub-regions, thereby generating coded data of each virtual image frame including plural types of image information.