A Quantization-Based Self-adaptive Digital Watermarking Technology

Recently, the development of multimedia storage and transmissiontechnology, especially the popularization of the Internet technology push thedevelopment of the digital media application, many types of multimediaworks such as image, video and music can be conveyed in a new way ofnetwork. These technologies bring people many conveniences, but they alsobring us some large side effects, for example, anybody can get the originalproducts of others easily, especially digital products such as images, music,films. Someone can copy and tamper the original works arbitrarily underdisagree, as infringes the author's copyright. How to protect the copyrighteffectively and solve the problem of information safeties on network is aurgent subject.Under this condition, as a kind of technology to solve multimediainformation security problem on network, digital watermarking technologycomes up into being. It embeds watermarks into the digital Medias, and thencarries out the functions such as information hiding, storing, and copyrightsafeguarding by tracking the use of the image by detecting the watermarks.At present, watermark technology becomes a kind of effective means tomultimedia copyright authentication and its integrity safeguarding.This paper takes still gray scale images as example and firstly introducesthe background and the phylogeny of the digital watermarking technology.The digital watermarking technology exists as an important embranchmentof the information hiding field. Since digital watermark technology wasproposed in 1993, have already become an independent interdisciplinarytheoretical system after going through the development for many years. Itcontains many technology and theory in many fields such as mathematics ,information hiding technology, cryptography, communication theory, andcomputer figure .In the part that is correlated with digital watermarktechnology in the introduction, this article gives the definition of the digitalwatermark: the digital watermark is a digital signal or mode which isinlayed in other data (constellation master data ) for ever, and does notinfluence the usability of the constellation master data . On the foundationthat is defined, the article has summarized digital watermark's basic theoriesframe, categorized method, common attack method and the method forassessing and testing. The article fetches the most popular vision treatment technology-DCT atpresent into digital watermark technology and bring forward a digitalwatermark solution which is self-adaptation and based on quantization in acreative way. The scheme is made up of following step mainly: (1) Dividing host image and watermark image into pieces and varying byDCT; (2) Utilizing a kind of Chaos system to make the watermark array; (3) Quantizing the DCT coefficient and embedding the watermark array inthe primitive image through the self-adaptation; (4) Distilling and testing he performance of the watermark signal. One intact digital watermark besides embedding , drawing andmeasuring of the watermark scheme, has a lot of work is it do to want, forexample choosing of digital watermark array, imbed course quantizationstep long sureness , choice of position that watermark was embed ,etc.Because of such understanding, the article has carried on overall analysisand studied to the characteristic of the human vision system. Thecharacteristic of the human vision system is the link that any picturetreatment technology must think over and the digital watermark technologyis no exception. In order to make the characteristic of the human visionsystem well combine with digital watermark technology, this article hascarried on overall and careful analyzing and researching to the systematictheory of human vision at first. On the foundation of explaining aesthesiacourse to the color of the physiological structure of the human eye and buildthe human eye vision model. About modulation of the watermark, thisarticle puts forward the Chaos method. And using certain space, this articlecarries on a comparatively detailed explanation and analysis to DCTcoefficient, thus imbeds the watermark signal to the high-frequency weightof DCT coefficient. These work not only job pave the way for later stagesuch as this text, but also play important part in the research of the digitalwatermark. Dispersed cosine varies DCT and quantization technology has strongvitality in image processing and encoding. Combining quantization togetherto the technology of DCT, and using human eye vision masking to confirm...