Improved Spread Spectrum multibit watermarking

This paper presents a Multibit Improved Spread Spectrum modulation (MISS) by properly adjusting the energy of the pseudo random sequences modulated by Code Division (CDM). We extend the one-bit spread spectrum watermarking approach proposed by Malvar and Florencio [1] to multibit watermarking by using an optimization procedure to achieve the best performance possible in robustness and transparency while mitigating the cross correlations among sequences and the host interference. The proposed multibit approach also tradeoffs the resulting watermarking distortion with the host interference rejection. We describe the improved modulation method and present results to illustrate the performance.