Detection for multiplicative watermarking in DCT domain by Cauchy model

In the last decade, the requirement for copyright protection of digital multimedia has become more and more urgent. As an efficient method to address this issue, watermarking has gained a lot of attention. To watermarking system, detectors have an important influence on its performance. In this paper, we propose a new optimal detector to multiplicative watermarking in the discrete cosine transform (DCT) domain, which is based on Cauchy models. Furthermore, theoretical analysis is also presented. The performance of the new detector is confirmed by various experiments.