7 - An adaptive and clustering-based steganographic method: OSteg

Abstract

In this chapter, we propose a novel adaptive spatial steganographic method based on Otsu clustering method (hence named OSteg). It is based on clustering pixels values to restrict the embedding alteration only to rich-textured blocks. The security of the proposed data hiding method is enhanced through exploiting a nonlinear system, that is, Ikeda system. The embedding of a secret message is carried out in two steps, a preprocessing phase and an alteration phase. For the classification and the undetectability evaluation of OSteg, the spatial domain color rich model (SCRM) is used. ROC curves and the probability of classification error of OSteg are established and compared with four well-known embedding methods. The proposed method outperforms the current state-of-the-art schemes in terms of probability of error, which implies the high undetectability of OSteg for the tested payloads (9.1553e−05⩽payload⩽0.0209).