1. An image processing apparatus comprising: a color information acquiring unit that acquires a target color information, wherein the target color is a corporate color and or a main color of a commodity main color included in the captured image; a region recognizing unit that recognizes a subject region, of a digital image, having a color within a prescribed range from the target color, the digital image being read from an image database in which a plurality of digital images are stored; and a converting unit that converts the color of the recognized subject region into a-luminance signal and a color difference signal and replaces the color difference signal of the color of the recognized subject region with a color difference signal of the target color, with the luminance signal being preserved.