There is provided with an image processing apparatus for extracting an object region from an image. An image acquisition unit acquires an image. A designation acquisition unit acquires designation of one or more extraction colors that belong to the object region of the image and designation of one or more non-extraction colors that do not belong to the object region of the image. A derivation unit derives a color conversion parameter, based on the extraction color and the non-extraction color. A conversion unit converts a color of the image based on the color conversion parameter. An extraction unit extracts the object region from the image, based on the image and the extraction color after the conversion.