用于篡改定位的可逆数字水印算法

Reversible digital watermarking algorithm for tampering localization

提出一种基于整数小波变换的可逆数字水印算法,将基于图像内容的水印嵌入载体图像,依赖于整数变换特性实现算法可逆,利用提取的水印与由图像本身局部特征生成水印的差值来定位篡改。实验表明,提取水印后可无失真地重构原始载体。即使含水印载体遭到人眼不可见的篡改,仍可在重构的载体图像中直接地显示发生篡改的区域。

In this paper,an IWT-based（ Integer Wavelet Transform） reversible watermarking method is proposed. A content-based watermark is embedded into the host image. Reversibility of this algorithm relies on characteristic of integer transformation; difference between extracted watermark and the watermark generated from specific coefficients which represent local feature of host image is applied to tampering localization. The experimental results show that it can recover the host image after extracting the watermark from the watermarked host image. Moreover,the tampered position can be localized explicitly and directly in the reconstructed host image even if the watermarked image was attacked by an invisible tampering.