1. An imaging device comprising: a light source control unit configured to control light sources to irradiate a body with irradiation light of a luminance level greater than a luminance level of air surrounding the body; an imaging element configured to perform photoelectric conversion on a pattern of light scattered through an inside of the body; a sensitivity adjustment unit configured to adjust imaging sensitivity of the imaging element; and an image generating unit configured to generate an image that excludes luminance level deterioration regions by replacing the luminance level deterioration regions with a reference image generated at a different sensitivity.