Three components are provided to achieve the goal. First, according to contrast and luminance characteristics, the capacity evaluation is provided to estimate the maximum embedding capacity of each pixel. Then the minimum-error replacement method is adapted to find a grey scale as close to the original one as possible. Finally, the improved grey-scale compensation, which takes advantage of the peculiarities of human visual system, is used to eliminate the false contouring effect. Two methods, pixelwise and bitwise, are provided to deal with the security issue when using the proposed model.
Experimental results show effectiveness and efficiency of the proposed model.
The authors provide an overview of information hiding, including steganography, digital watermarking and fingerprinting. They start off by clarifying the terminology, then describe a wide range of techniques that have been used in applications both ancient and modern. Finally they describe a number of attacks against these techniques and formulate general principles and theory. The authors describe their approach for enabling multilateral security in distributed applications, where users can configure their systems and negotiate on security requirements in heterogeneous roles. The system platform is developed in Java and described in detail.