Abstract: Obtaining a needed image has been difficult with conventional technology. A needed image can be obtained by an imaging device including an optical signal acquisition unit that performs imaging and acquires an optical signal, an original image acquisition unit that acquire two or more different original images using the optical signal, a selection unit that acquires one output image from candidate images including the two or more original images acquired by the original image acquisition unit, and an image output unit that outputs the output image acquired by the selection unit.

Abstract: In some cases, it is desirable for a camera head to be small. A camera head has an elongated shape, and is used for imaging an imaging area located in a vicinity of a leading end portion in a longitudinal direction. The camera head includes: a camera module; two or more light source units disposed at positions farther from the leading end portion than the camera module is in the longitudinal direction; and a light guide unit disposed radially outside an outer surface of the camera module and configured to guide light emitted from each of the two or more light source units to the vicinity of the leading end portion so that the imaging area is irradiated with the light, and at least two light source units of the two or more light source units are located at different positions in the longitudinal direction. With such a configuration, the camera head can be made even smaller.