For Image Authentication Semi-fragile Watermarking Scheme

Digital watermarking technique is a whole new mean to guard information security.It has been a strong method for copyright protection and authentication on multimedia.And it involves the theory on communication and information,digital image processing,network security and so on.It is of high academic value and economic value.Semi-fragile watermarking technique is an important branch of digital watermarking.It can tolerate general signal processing,detect any spiteful tamper on marked multimedia data,locate spatial regions within an altered image,and even can estimate what kind of modification had occurred and recover the tampered data.In this paper,the background,the concept,the general framework and the research trend of authentication watermarking(known as fragile watermarking and semi-fragile watermarking) technology is roughly described,the emphasis is on the analysis of authentication watermarking classified by the spatial and the transform domain,also their advantages and disadvantages are analyzed,in addition,common attacks applied to authentication watermarking are summarizedIn this paper,two kinds of semi-fragile watermark are embedded in a image in wavelet domain,which achieve the purpose of image composition authentication or multi-purpose protection.Through numerous experiments, the rules are summer up,so that there is a image charts about the attacks on the specific characteristics.In the same way,we can have a more accurate analysis distinguish types of attacks and distortion measure of its capacity.