A New Steganographic Distortion Function with Explicit Considerations of Modification Interactions

Abstract

Conventional steganographic schemes are based on optimizing an additive distortion function, which is defined by summing up the cost of modified pixels. Using such schemes, pixels with lower costs will be selected for modification. However, the interactions of embedding changes are not explicitly considered in the distortion function. In this paper, we propose a new framework for steganography that incorporates a term considering interactions of embedding changes in the distortion function. An algorithm is designed to minimize the distortion with an approximal but efficient solution using auxiliary costs. The proposed framework can eliminate the ambiguity in the definition of additive distortion caused by updated costs. Experimental results show the proposed framework is more resilient to steganalysis compared with the schemes with a conventional additive distortion function, and it works as best as the embedding schemes with synchronized modifications.