摘要：Though image data hiding (Digital watermarking) as a tool for copyright protection is
quite recent, a great deal of research has been carried out mainly addressing the
development of robust, yet unperceivable, watermarking strategies. As it is now
becoming evident, however, other important issues have to be analyzed in order to make
watermark-based copyright protection feasible. Among them, the analysis and
comparison of the performance of additive embedding rule, multiplicative embedding
rule and fusion embedding rule plays a mayor role. In this paper, the watermarking is
assumed to consist in the modification of a set of full-frame DCT coefficients. The
watermark channel is modeled by letting the watermark be the signal and the original
image DCT coefficients the noise introduced by the channel. To derive the capacity of
each coefficient, the channel transition matrix is computed. An evaluation of the number
of bits that can be hidden within a digital image by means of DCT domain watermarking
is given. These calculated results are derived by using three embedding rules,
respectively. Experimental results show that different performance of three kinds of
embedding rules, these performance have offered basis on which we use these
embedding rules rationally.
