Abstract: In order to solve the contradiction between the robustness and invisibility of the digital image watermark, a new digital image watermarking algorithm is presented. Based on the character that the greater singular value of the Hermit matrix is not sensitive under some perturbation, the algorithm chooses the greater singular value of the original image as the watermark, which is both invisible and has better resistivity to the attack of noise, geometry and filt on the image.

Key words: matrix perturbation, digital watermark, invisibility, robustness