An image processing apparatus includes circuitry to receive visible image data obtained by reading of a subject with a sensor having sensitivity to visible light in a visible wavelength range and invisible image data obtained by reading of the subject with a sensor having sensitivity to invisible light in an invisible wavelength range. The circuitry generates image data for displaying, in a designated color, a portion of the visible image data corresponding to a designated region of the invisible image data. The designated region has an absorption rate equal to or higher than a predetermined absorption rate.