An image processing device includes: an image acquiring unit that acquires first and second image groups, each image sharing a common part of a subject with the other image in different first and second directions; a calculating unit that calculates, as a shading component, a ratio of luminance of an area in one or more images, the area sharing a common subject with another area including a flat area whose shading component is constant in a single image other than the one or more images, to luminance of the another area, for each of the first and second image groups; and a correcting unit that performs a shading correction on shading areas in the images using the shading component. The shading component includes a normalized shading component based on luminance of the flat area, and a non-normalized shading component based on luminance of an area other than the flat area.