An adaptive digital watermark based on a tree structure using the human visual system

Digital watermarking has been proposed as a way to claim ownership. In this paper, we propose a blind watermarking that does not require an original image in the detection process. We construct an image-dependent watermark and embed it in the most significant discrete wavelet transform (DWT) coefficients, which are determined by using hierarchical tree structure. When the locations of such coefficients are changed due to image manipulations, the tree structure allows the watermark detector to recover the set of embedded coefficients. We also propose a new frequency band-wise weight of the human visual system (HVS). With this weight, we can increase the robustness of watermarks without deterioration of perceptibility. In our experiments, the robustness of the proposed scheme is better than the one without weighting.