Perceptual digital watermark of images using wavelet transform

In this paper a perceptually based watermarking technique for image is proposed. Based on the just-noticeable difference model in wavelet domain, watermark is inserted in wavelet coefficients and its amplitudes are controlled by wavelet coefficients so that watermark noise does not exceed the just-noticeable difference of each wavelet coefficient. Meanwhile, the order of inserting watermark noise in wavelet coefficients is same as the order of visually significance of wavelet coefficients. Hence, our approach is adapted with image content and the transparency and the robustness of digital watermark can be guaranteed. Experimental results show our approach has excellent performance in the quality of watermarked images and the robustness of watermark.