Image watermarking based on color quantization process

The purpose of this paper is to propose a color image watermarking scheme based on an image dependent color gamut sampling of the L*a*b* color space. The main motivation of this work is to control the reproduction of color images on different output devices in order to have the same color feeling, coupling intrinsic informations on the image gamut and output device calibration. This paper is focused firstly on the research of an optimal LUT (Look Up Table) which both circumscribes the color gamut of the studied image and samples the color distribution of this image. This LUT is next embedded in the image as a secret message. The principle of the watermarking scheme is to modify the pixel value of the host image without causing any change neither in image appearance nor on the shape of the image gamut.