A Quantitation Method to the Imperceptibility of Hiding-Vector in Multi-dimensional Hiding Space

Currently, few general methods have been suggested to quantitate the imperceptibility among various hiding algorithms. Especially, it is a challenge to quantitate the imperceptibility of the hiding-vector, which is consisted of orthogonal hiding algorithms in the multidimensional hiding space. In this paper, a novel model of general imperceptibility quantitation was proposed. According to this model, a quantitation method based on the relative entropy was designed. It is proved under this quantitation method that there exists the global maximal imperceptibility for any specified hiding-vector capacity. An optimization algorithm was proposed to approach this maximum by adjusting the allocation of secret message into each components of the hiding-vector. Experiments with VoI Pand bitmap multi-dimensional hiding space validated the effectiveness of the designed quantitation method and the proposed optimization algorithm.