基于提升小波变换的图像认证数字水印

目前基于小波变换的数字水印算法主要根据频域小波系数的幅值大小确定是否嵌入水印,这种算法的缺点是嵌入水印后的图像的视觉透明度不够好.该文提出了一种基于提升小波变换的盲水印算法,利用提升小波变换将原始图像进行多分辨率分解,利用低频部分系数来生成水印,基于密钥来选取高频部分的小波系数,并根据小波系数的奇偶性嵌入水印.在水印提...

Semi-fragile Image Authentication Watermarking Using Lifting Wavelet Transform

At present,digital watermarking algorithms based on wavelet transform decide to embed watermarking whether or not mainly in accordance with the amplitude of wavelet coefficients in frequency domain.However,the visual effect of watermarked images processed by this kind of algorithms is not good enough.This paper proposes a novel blind watermarking algorithm based on lifting wavelet transform,it makes multi-resolution decomposition of original images with lifting wavelet transform,and generates watermarks with low frequency coefficients.Then it chooses wavelet coefficients of high frequency based upon secret key and embeds watermarking according to the coefficients＇ parity.During the watermarking extraction process,it can correctly localize the tampering on the basis of the location determined by the secret key and the parity of wavelet coefficients.The algorithm proposed in this paper is simple and reliable,and experiments show better effect compared with other algorithm.