1. An image processing apparatus that generates a color image containing multiple color luminance information of each pixel using a color mosaic image that contains single color luminance information of each pixel obtained from single-chip imaging elements as a plurality of photoelectrical converted pixels, the image processing apparatus comprising: a color plane separator unit that separates the color mosaic image into multiple color planes having the same color; a coordinates conversion unit that calculates sampling coordinates for the color mosaic image from a pixel position generated from the color mosaic image using a coefficient of an expression of an image processing of the color mosaic image during execution of a color image process for the color image; a sampling unit that interpolative-generates color luminance values of same color pixels in the color planes as calculated by the coordinates conversion unit from pixel position values of the sampling coordinates; and a color image generation unit that synthesizes interpolated values of each of the color planes provided by the sampling unit.