Digital Image Watermarking Technology Based On Transform Domain

With the development of network technology, it is easier to copy, falsify and faxthe digital product. The watermark technology applied in the image protection hasdrawn intensive attention from academic communities. In general, the watermark isembedded in the pixel information or transformed coefficients directly. Comparedwith the watermark algorithm, the watermarking algorithm in transformed domaindoes not only have good Intellectual and large watermark capacity, but also haverobustness to general compression technology.This paper mainly studies the imagewatermarking algorithm of copyright protection in transform domain, the maincontribution is proposing a well robust watermarking based on DWT-DFT which canapplied to image copyright protection.Firstly, the paper presents the background and development of digitalwatermarking technology, introduces digital watermark theoretical, introduces severalwatermark technology based in transform domain, explicitly introduces general modelfor digital image watermarking technology in transform domain. Secondly, a wellrobust watermarking based on DWT-DFT is proposed which has simple method toembed watermarking, extract the naked eye recognizable watermark and use templatematch method so as to secure the watermark against geometrical attack. Finally, thepaper presents an algorithm that embed the watermark directly into the DCcomponent in wavelet domain. While limiting the quantity of embedded watermark,this algorithm is effectively robust which can be used in image copyright protection.This thesis conducts the algorithm simulation and validates the effectiveness of theproposed algorithm.