Research of Dual Watermarking Technology for Digital Image

Digital image watermark has been studied as object. It analyzed the typical digital watermark algorithms based on the space domain and transform domain and key researched watermarking algorithm based on discrete wavelet transform. It has designed and improved blind watermarking algorithm and color image watermarking algorithm. Finally, based on the two improved watermarking algorithm, it has designed a dual watermarking algorithm. Both are separated but related. It authenticates dual watermarking algorithm in addition to subjective visual evaluation, but also use numerical objective evaluation and quantitative analysis. Experimental results show that this dual watermarking algorithm combines with robustness and concealment.