A Digital Watermarking Method Using Binary Cluster

In this paper, we propose a wavelet-tree-based watermarking method for copyright protection by using distance vector of binary cluster. Wavelet trees are classified into two clusters using the distance vector, which is obtained from the two smallest coefficients of a wavelet tree, to denote binary watermark bits. The trees are classified into two clusters so that they exhibit a sufficiently large statistical difference based on the distance vector, which difference is then used for subsequent watermark extraction. The watermark is embedded in the insignificant coefficients of wavelet trees, and uses the difference of the distance between the two smallest wavelet coefficients to extract the watermark. Experimental results show that the proposed method is very efficient in resisting various kinds of attacks and the watermarked image looks visually lossless.