1. An image processing method for carrying out image processing on an interimage-difference image obtained by subjecting two desired images from among two or more images taken of the same subject to interimage processing and which represents the substantial difference between said two images, wherein said image processing carried out on said interimage-difference image is image processing by which the substantial difference between said two images represented therein is enhanced relative to artifacts arising due to misalignment of structural positions contained within said two images.