基于小波变换的信息隐藏技术的改进

数字水印的稳健性体现了水印在数字文件中的生存能力，当前大多数算法均具有一定的稳健性，但是如果同时运用各种图像攻击，那么大部分算法均会失效。如何寻找更加稳健的水印算法仍是一个急需解决的问题。文中首先介绍了小波分析原理和数字水印算法，并且进行了仿真。由于Arnold变换具有周期性，文中重点讨论了一种基于小波分析的数字水印改进算法，该算法利用Arnold变换和亚放射变换进行双重图像置乱，能防止多次Arnold变换还原水印图像的攻击，经过仿真验证，具有更好的抗JPEG压缩攻击。

Study on Digital Watermarking Technique based on Wavelet Transform

Robustness of digital watermarking embodies the viability of the digital document. Current algorithms mostly have certain stability, but if by multiple image attacks, these algorithms would fail. How to find a more robust watermarking algorithm is still an urgent task. This paper describes the theory of wavelet analysis and digital watermarking algorithm, including the simulation. Because of the cycle of Arnold transform, this paper focuses on a digital watermarking algorithm based on improved wavelet transform. This algorithm, through Arnold transform and sub-radiation transform, could conduct dual image scrambling, prevent restoration of the watermarked image from multiple Arnold transforms. Simulation and comparison indicate that this algorithm is of better resistibility to the attack of JPEG compression.