一种基于提升方案小波和小波块的图像水印算法

数字水印技术是多媒体信息安全领域的一个重要研究课题。文章提出一种基于提升方案小波和小波块的图象水印算法。首先，利用提升方案小波对宿主图像和水印图像进行分解，同时利用小波系数的树结构，将宿主图像的小波系数块按纹理密度分成两类，并根据嵌入位置所隶属的小波块的纹理强弱，嵌入不同强度的水印信息，这在一定程度上保证了所嵌入水印在不可见性前提下的极大鲁棒性。实验结果验证了所提出算法的有效性。

A Image Watermarking Scheme Based on Lifting Scheme Wavelet and Wavelet Blocks

Digital watermarking technique is an important research field of multimedia information security. A robust image watermarking technique of wavelet transform based on lifting scheme wavelet and wavelet blocks is proposed. First, the original image and the watermark image are decomposed by wavelet transform based on lifting scheme, in terms of tree structure of the wavelet transform coefficients ,the original image wavelet blocks are divided into two kinds according to the intensity of wavelet blocks texture. Owing to the embedded location is belonged to different transform block, the watermark image frequency coefficients are embedded into the original image in terms of different intensity, thus embedded watermark is maximum robust and invisible. According to the experiment result, it is shown that the approach is valid.