Provided is an image processing apparatus or the like which can accurately extract a blood vessel in a specified depth from an image acquired by an endoscope and can highlight the blood vessel. An image processing apparatus 1 includes a narrow-band image acquisition unit 101 to acquire at least three narrow-band images with different center wavelengths in an image processing apparatus to process an image acquired by capturing of a living body, a depth feature data calculation unit 102 to calculate depth feature data, which is feature data correlated to a depth of a blood vessel in the living body, based on a difference, between the narrow-band images different from one another, in variation of signal intensity due to an absorption variation of light with which the living body is irradiated, and an enhanced image creation unit 103 to create, based on the depth feature data, an image in which a blood vessel is highlighted according to a depth of the blood vessel.
