一种自适应的盲水印方法

目前数字水印算法多局限于在图象中嵌入特定的标记,并通过改变空域值或频域系数值来达到目的.提出了一种新颖的自适应盲水印方法.首先基于小波变换的零树结构,找出重要系数,然后根据重要系数所在区域的特性构造出一个序列信息,再利用置乱变换最终得到水印信息,而不修改图象本身的任何特征.因此水印的不可见性从根本上得到了保证.其中,重要系数的选择是自适应于图象的,并且水印的检测是不需要原始图象的盲检测.实验证明该方法的鲁棒性较强,是一种行之有效的方法.

A METHOD OF SELF-ADAPTIVE BLIND WATERMARK

A method of self adaptive blind watermark is proposed.Significant coefficients are found based on the zerotree structure of wavelet transform.And then a sequence information is constructed according to the characteristics of the domain which the significant coefficients are located.Finally the watermark information is obtained after scramble transform.The process does not change any characteristics of the image itself.So the imperceptibility of the watermark is ensured at all.Moreover,the selection of the significant coefficients is self adaptive to the image,and the detection of the watermark is a blind detection without the original image.The experimental result has shown that the robustness is strong.So the method is effective.