摘要：In this paper, we presented a Rao hypothesis detector by modeling Cauchy distribution for the NonSubsampled Contourlet Transform (NSCT) subband coefficients in the field of additive spread spectrum image watermarking. Firstly, the NSCT subband coefficients were modeled following the Cauchy distributions. Secondly, a blind Rao test watermark detector was derived in the NSCT domain. Finally, the robustness of the proposed watermarking scheme was evaluated. Experimental results show that the proposed Rao detector guarantees the lowest probability of miss under the given probability of false alarm.
