New blind image watermarking in DCT domain

We propose a new blind image watermarking method in the discrete cosine transform (DCT) domain, which is widely used in compression applications and consequently in digital distribution networks. Four watermarking schemes are presented and experimentally analyzed, two of them use fixed parameters and the others are adaptive. The characteristics of human visual systems (HVS) are exploited in two adaptive watermarking schemes, so as to achieve high visual quality of watermarked image and robustness of watermarking. Moreover, the proposed algorithms can be easily implemented by existing software or hardware systems only with small modification.