1. An image processing apparatus comprising: an image dividing unit for obtaining a plurality of first sub-image data items corresponding to a plurality of first sub-images that are obtained by dividing a first image corresponding to first image data; a noise reducing unit for obtaining a plurality of second sub-image data items corresponding to a plurality of second sub-images by reducing noise in the first sub-images from the first sub-image data items that are obtained by the image dividing unit; and an image synthesizing unit for obtaining second image data corresponding to a second image corresponding to the plurality of second sub-images from the plurality of second sub-image data items that are obtained by the noise reducing unit.