Research And Realization Of Digital Watermarking Algorithm For Binary Images Based On Wavelet Transform

With the development of E-Commerce and E-Government Affairs,there are more and more digital products in the form of binary images exist and transmit in network,such as certificates of patent,classified documents,checks etc.The Copyright protection to these significant files will be more and more indispensable.However,the existing digital watermark algorithms are only suitable for certain specific situations.Especially,the existing image watermark algorithms are mainly suitable for gray-scale images and color images,not binary images.Binary images have little redundancy in vision,low information hiding capacity and other features,but they are not taken into account,so the existing image watermark algorithms can't be directly used in binary images watermark technology.Therefore,the research of binary images watermark technology is quite necessary.First,this article studies the state and evolution of digital watermark technology in depth,and does some analysis and comparison of typical binary images watermark algorithms.In order to improve the security of watermark information,a new pretreatment algorithm with high security is presented based on logistic map and affine transformation.If the aggressor don't know the rotation matrixes and initial values which is used to produce the sequence of Logistic,he can't crack the skipped of watermark . At the same time , by the analysis of the application of wavelet transformation technology in the fields of digital watermark,we choose the middle frequency coefficients in DWT as the embedding positions by Zig-Zag algorithm.In order to improve the robustness of watermark algorithm,we set the controlled parameter by the distribute of 0&1 pixels in watermark image to adjust the embedded procedures of watermark.Experimental result show that,the new watermark algorithm has good imperceptibility,high security and robustness.