The image processing device performs processing on a shadow in an image of an object, and includes: an image information obtaining unit obtaining information about an image of the object, the information including luminance information about luminance of light from the object and polarization information about polarization of the light from the object; a shadow area extracting unit extracting an attached shadow area and a cast shadow area from the image of the object based on the luminance information and the polarization information, the attached shadow area appearing on the surface of the object depending on an angle of incidence light, and the cast shadow area appearing on the surface of a material body other than the object when the light is blocked by the object; and an output unit outputting information identifying the attached shadow area and cast shadow area.