1. An image processing device comprising: an edge-enhancing image enlarger for converting an input image having a first resolution to a high-resolution image having a second resolution, edges included in the input image being enhanced in the high-resolution image; a difference calculator for determining differences between the high-resolution image and the input image; and a high-resolution image corrector for correcting the high-resolution image by diffusing the differences to pixels in the high-resolution image, thereby generating a corrected image, and outputting the corrected image as an output image.