1 : An image quality evaluation method comprising, based on a statistical quantity of alternating-current components within a pixel group in a first image and that within a pixel group in a second image at the same position as that of said pixel group in said first image, evaluating image quality of said second image, wherein said statistical quantity of alternating-current components within the pixel group is an average of absolute differences within an image group, each of said differences being an absolute difference between an average of pixel values within said pixel group and each pixel value within said pixel group.