基于Turbo码的DCT域直流分量图像水印算法

文中提出了一种基于Turbo码的DCT变换域直流分量图像水印算法。首先对原始水印信息进行伪随机置乱，接着对置乱的水印进行Turbo编码并进行BPSK调制，生成待嵌入的水印信息。在充分考虑人眼视觉特性的基础上，分别采用两种方式将水印嵌入到DCT变换系数的De分量中，并进行性能比较。丈中对算法在多种常见的攻击如JPEG压缩、噪声、剪切、滤波下进行了仿真。实验结果表明，利用该算法实现的水印具有良好的不可见性和鲁棒性。特别是非自适应加性嵌入方式对JPEG压缩攻击具有很强的鲁棒性。

DC Component Image Watermarking Algorithm of DCT Domain based on Turbo Code

In this paper, a DC component image watermark algorithm of DCT transform domain based on Turbo code is proposed. The original watermark is pseudo randomly scrambled first, and then the scrambled watermark is coded by Turbo code and modulated by BPSK to generate the watermark information, which shall be embeded in the image. In fully considering the visual characteristics of the human eye, two ways for embedding the watermark in the DC component of DCT transform coefficient are compared for their performances. Simulation on the algorithm under several attacks, such as 3PEG compression, noise, shearing and filtering, shows that the algorithm is of good invisibility and is robust in implementating the watermark, especially the non-adaptive additive embedding mode is much more robust to JPEG compression.