Research On Digital Watermarking Algorithm Based On Structural Similarity And Contourlet

With the rapid development of information technology and internet, they provided immense facilitating to multimedia information access and exchange, but the digital technology has some features, such as accurate, low-priced, it is possible for the large-scale duplication at the same. It had a negative impact on copyright protection, because Digital products can easily be tampered with, illegal dissemination and deliberate attacks. How to protect copyright has attracted people's great concern. The digital watermarking technique has been regarded as a promising way to protect the copyright of digital products. It becomes a hot spot in a research field of the information security.This paper proposes the digital watermarking algorithm based on SSIM and based Contourlet. They included the watermarking embedding and extraction algorithms, as well as the watermark invisibility and make a variety of attacks for the image after embedding watermarking, such as additive noise, filtering, shear and so on, thus give a result of the evaluation.The main function of HVS is highly adapted for extracting structural information from a scene; the structural similarity simulates the overall function of HVS from a high level, therefore this paper use that a measure of structural similarity can provide a good approximation to perceived image quality.According to this theory, and combined with human visual system features, in this paper, we proposed the digital watermarking algorithm for image authentication,which based on SSIM, this algorithm can embed watermarking in some particular locations by marked some palaces which can be changed in the original image. Experimental demonstrate the effectiveness of the proposed method.Trough considering the important wavelet tree structure, we use the Contourlet transform, and according to parent–child relationship in Contourlet coefficients, the important sub-tree based on controulet , which is formed .Embedding watermarking in the important sub-tree. This algorithm choose important coefficient through setting up threshold value. Experiment shows this algorithm of the feasibility.