Abstract: Aiming at the problem of poor robustness of color image watermarking algorithms under filtering attacks, we proposed a dual-color robust watermarking algorithm based on tensor decomposition and joint entropy. Firstly, the color carrier image was tensor-decomposed as a whole to obtain its tensor feature map and divided into blocks. Secondly, joint entropy was used to extract the feature map sub-blocks with better shadowing. Finally, the watermark information was embedded into the U matrix of the selected block after singular value decomposition (SVD). The experimental results show that the peak signal-to-noise ratio of Lena images is more than 39 dB. The algorithm  can not only effectively resist image filtering attacks, with a maximum NC value of 1.000 0, but also has strong robustness against other conventional image attacks and geometric attacks.

Key words: image watermark, tensor decomposition, joint entropy, singular value decomposition (SVD)