Exploiting the cross-correlation of RGB-channels for robust watermarking of color images

In the last few years, digital watermarking has been proposed as a solution to the problem of copyright protection of multimedia data against unauthorized uses. In the field of image watermarking, research has been mainly focused on grey-scale image watermarking, whereas the extension to the color case is usually accomplished by marking the image luminance, or by processing each color channel separately. In this paper, a DCT domain technique expressly devised for watermarking of color images is presented, which exploits the characteristics of the human visual system and the correlation between the RGB image channels. Experimental results are presented to demonstrate the validity of the new approach with respect to algorithms operating on image luminance only