A Novel Steganography Scheme Based on Asymmetric Embedding Model

摘要

Recently, many high security steganographic schemes have been developed to approximate non-additive distortions with consideration of mutual adjacent modification influences. However, their security performance behaves volatilely and is very sensitive to the heuristically designed parameters and the initial additive distortion function. To make a stable security performance and to further improve the embedding security, a novel model-based steganographic scheme is proposed by incorporating the adjacent embedding information with no dependence on the heuristic parameters. We first divide the cover image into several interleaved sub-lattices, and then optimally embed message into each sub-lattice in sequence. In each sub-lattice, the embedding change rates for each pixel are optimized by utilizing the adjacent modifications as priori knowledge. During the optimization process, a novel asymmetric probability model is designed to simultaneously tackle with two inequivalent change rates for modifying the cover pixel by +1 and - 1. Experimental results show that the proposed scheme can rival or outperform the prior arts, and moreover, can provide a stable security performance.