An Enhanced Multiplicative Spread Spectrum Watermarking Scheme

Watermarks can be embedded into the host contents by multiplicative spread spectrum (MSS) methods. However, the interference from the host contents hinders the successful detection of the embedded watermark. This interference can be compensated at the embedder, or be exploited at the detector to improve the detection rate. In this paper, we first derive the optimum decision rule for watermarking in the discrete cosine transform domain, and then proceed to present an enhanced MSS scheme that compensates the host interference at the embedder. In our scheme, the host interference to be compensated is a generalized correlation tailored to the optimum decision rule. Its effectiveness is validated through both theoretical analyses and experiments