Color image watermarking using channel-state knowledge
Josep Vidal, Maribel Madueno, Elisa Sayrol · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2002
This work concentrates on the problem of watermarking embedding and blind optimum detection in full-frame DCT domain using channel-state knowledge concepts. Minimum length sequences are used to embed the watermark information in the color components. Each chip of the sequence is inserted in a random-like fashion in those coefficients that ensure imperceptibility, robustness and a very low probability of error in detection. As it will be shown the power of the watermark has to be distributed among the symbols not only considering imperceptibility but also to improve the detection process. Furthermore, two solutions are proposed to improve the robustness against cropping operations.