Research on Multiple Digital Watermarking Algorithm Based on Double Scrambling

Multiple digital watermarks were embedded into the color carrier image based on the YIQ color space. In the color space, the Y component can independently display the brightness information of the color image, and embedding watermarks in the Y component has little effect on the other two color components. So this paper used haar wavelet to perform 3-level discrete wavelet decomposition on the Y component of the color carrier image, and two robust watermarks were embedded in LL3 and HL3 layers of Y component respectively for copyright protection and authentication of digital products. The authentication watermark was embedded in HL2 layer of the Y component to locate the areas where the color carrier image has been tampered with maliciously. Then through a series of simulation experiments to test, it can be seen that the algorithm in this paper has strong robustness from the analysis of experimental results. It not only can achieve copyright protection, but also can achieve the function of tampering positioning.