This paper proposes a new adaptive watermarking scheme for digital images, which has the properties of blind extraction,\ninvisibility, and robustness against attacks. The typical scheme for invisibility and robustness consisted of two main techniques:\nfinding local positions to be watermarked and mixing or embedding the watermark into the pixels of the locations. In finding the\nlocation, however, our scheme uses a global space such that the multiple watermarking data is spread out over all four lowestfrequency\nsubbands, resulting from n-levelMallat-tree 2D (dimensional) DWT, where n depends on the amount of watermarking\ndata and the resolution of the host image, without any further process to find the watermarking locations. To embed the watermark\ndata into the subband coefficients, weighting factors are used according to the type and energy of each subband to adjust the\nstrength of the watermark, so we call this an adaptive scheme. To examine the ability of the proposed scheme, images with various\nresolutions are tested for various attacks, both pixel-value changing attacks and geometric attacks.With experimental results and\ncomparison to the existing works we show that the proposed scheme has better performance than the previous works, except those\nwhich specialize in certain types of attacks.
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