The development of watermarking schemes in the literature is generally guided by a power constraint on the watermark to be embedded into the host. In a steganographic framework there is an additional constraint on the embedding procedure. It states that, for a scheme to be undetectable by statistical means, the pdf of the host signal must be approximately or exactly equal to that of the stegotext. In this work we examine this additional constraint when coupled with DC-DM. An analysis of the embedding scheme Stochastic QIM, which automatically meets the condition under certain assumptions, is presented and finally the capacity of the steganographic channel is examined.
Mark T. Hogan, Félix Balado, Neil J. Hurley