Hybrid additive watermarking and its decoders
With the rapid development of Internet-based media consuming, the piracy issue becomes urgent, which makes copyright protection a hot research topic. There exist various watermarking methods that are regarded as potential solutions to copyright protection. However, most of watermarking methods have different properties, and the combinatorial method is expected to make use of different methods advantages and to get a good tradeoff. In this paper, a novel hybrid watermark embedding rule is proposed to select the general additive embedding rule or the special additive embedding rule securely. The selection is controlled by a secret key, and the watermark is embedded into the Discrete Wavelet Transform (DWT) domain. With respect to the hybrid embedding rule, the novel optimum and locally optimum hybrid additive decoder is proposed, which is based on the minimum Bayesian risk criterion. And simultaneously, the performance of the optimum hybrid decoder is theoretically analyzed, with the DWT coefficients modelled as the generalized Gaussian distribution. Furthermore, the security of the proposed hybrid watermarking scheme is proved higher than that of existing schemes. Finally, empirical experimental results are given to prove the validity of theoretical analysis.
optimum and locally optimum hybrid decoder hybrid additive rule