1. An image generation method for generating image information of a third image C by using a first image A and a second image B having a resolution higher than that of image A, the method comprising: an image enlarging step that generates the third image C having the same resolution as image B by enlarging the first image A; a corresponding point estimating step that estimates presence or absence of a point in the second image B corresponding to each pixel position of the third image C and also estimates the position of the relevant corresponding point; and a corresponding image assigning step that assigns, to each pixel position in the third image C for which the corresponding point estimating step estimates that there is a corresponding point, image information of the corresponding position in the second image B.