Double watermarking examination based onKrawtchouk moment invariants and SVD and LWT
基于Krawtchouk不变矩和SVD-LWT的双重水印研究

In order to improve the robustness and transparency of the digital image watermarking, this paper proposed a color image double watermarking algorithm based on Krawtchouk moment invariants, singular value decomposition SVD and the lifting wavelet transform LWT. Firstly, the algorithm extracted green component from the RGB image for two level ascension wavelet transform. The invariance of Krawtchouk moment invariant to translation, rotation and scaling, and more, good local characteristics and reconstruction of Krawtchouk, which could calculate Krawtchouk moment invariants of the low frequency components to structure one watermarking system. And then, the transformation of the intermediate frequency component singular value decomposition, embedded chaos after scrambling watermark image of the singular value as another watermarking system. Simulation results show that this algorithm not only has good invisibility, but also has very good robustness to the common attack and geometric attacks, and it has application value.