RS Image Semi-Fragile Watermarking With Wavelet Packet

With the development of computer network technology and digitalmultimedia, which supply information for us timely, at the same time thequestion on security of digital information and authenticity are broughtforward. How to bring into effect measure of protect authenticity and securityinformation has paid great attention by academe, enterprise, government.Theconventional means of information security have their characteristic oflocalization, Semi-fragile digital watermarking technology supply neweffective means for protect authenticity and information security, digitalwatermarking not only ensure the watermark is not tampered or get rid of ,butalso resist some normal processing, for example: compression, somewatermarking means has the capacity of located the tamper. The method four departments: Firstly, generate watermarking, extractingedge characters from different resolution RS images with dyadic wavelet asthe zero watermarking; secondly, scramble watermarking, scrambling theimage based on a new method which was deduced from affine transformationand not only had better information cryptic character, but also was easilycomputed; thirdly, embed watermarking, the R,G,B bands of differentresolution multi-spectral image was decomposed by orthogonal waveletpacket,then embedded different intensity of watermarking in sub-bandswavelet packet coefficients separately, and during the course of embeddingwatermarking two private keys were generated; at last, inspect semi-fragilewatermarking, which includes inspecting whether the image included thewatermarking by using the keys attained form the course of embeddingwatermarking, and if it was a marked image, then extracted watermarking, atlast validated the degree of robustness by compressing, cutting, altering andadding noises to it, and located the tamper parts of the image.