基于混沌映射的自适应小波包水印算法

提出了一种基于混沌映射、小波包变换和空间扩频概念嵌入水印的一种新算法．首先对水印图像进行混沌映射，并利用小波包多级分解构造最优小波树各级时一频域系数和确定嵌入的级数，最终根据数字图像的特征，自适应分块确定水印嵌入的区域和强度，同时不改变原始图像本身的任何特征．实验表明，该算法对常见的图像处理和几何变换具有较强的鲁棒性。

Adaptive Wavelet Packets Watermarking Algorithm Based on Chaotic Mapping

In this paper we present a new digital image watermarking algorithm based on chaotic mappings, wavelet packets transform and the concept of spread spectrum. First, we process the watermark with a chaotic system. Then, we decide the bands to be embedded in. Finally, by the characteristics of the digital image, we ensure the areas and the strength of the embedded watermarking adaptively, while keeping the host image quality well. The experimental results show that the algorithm is robust to both general image processing techniques and geometric distortions.