1. A method of encoding gamut information into a marked image, comprising: transforming an image with a first gamut; mapping the transformed image to a second gamut to obtain a second-gamut image; determining a first residual image between the image with a first gamut and the transformed image; determining a second residual image between the transformed image and the second-gamut image; and separately encoding the first and second residual images within the second-gamut image, wherein the encoded first and second residual images may be decoded from a marked copy of the second-gamut image.