This image processing device operates by identifying a region that is in a similar image and has a pattern which is the same as a pattern appearing in a section of a reference image, and repeating an operation several times and the section and the region are superposed to generate a reduced-noise fragment, after which the reduced-noise fragments obtained for all of the regions of the reference image are combined to generate a reduced-noise image. When such an operation actually is attempted with an image processing device the regions corresponding to the sections in the reference image cannot be found from the similar image. Therefore, with the present invention the reduced-noise fragments are generated by performing spatial processing on the sections. Thus, reduced-noise fragments can be obtained reliably for all of the regions of the reference image, and noise can be removed from the reference image more reliably.
