中文摘要：

该文提出了一个抗噪声、几何失真和JPEG压缩攻击的鲁棒数字水印方案,首先对原始水印信息进行置乱变换,然后再进行Turbo码编码以及扩频、合成,产生CDMA水印信息,在充分考虑人眼视觉特性的基础上确定编码水印在DWT和DCT混合变换域的嵌入位置和强度。为了减小水印提取过程中多址干扰（MAI）的影响,通过采用好的编译码方法（Turbo码）降低接收机检测门限来实现。实验结果表明,应用该文提出的数字水印方案,水印的安全性有了很大提高,而且,在保证水印不可见的情况下,水印容量大大增加了。更重要的是,对剪切、平移、旋转等各种几何失真攻击以及噪音攻击、JPEG压缩、滤波等常见的信号处理都具有极强的鲁棒性,即使嵌有水印的图像遭受攻击后质量损伤严重,水印图像还是能够清晰地提取出来。

英文摘要：

In this paper, a digital watermarking algorithm resistant to the noise, geometric distortion and JPEG compression is proposed. Firstly, in order to enhance the security of the watermarking, the original meaningful binary image watermarking is scrambled with using Arnold transform. Then the scrambled watermarking is encoded by using Turbo code and CDMA technology. Taking into account the characteristics of human visual system （HVS）, the positions and strengths of embedding the image are obtained. In the process of watermarks extracting, there must be the influence of Multiple Access Interference （MAI）. By taking advantages of good encoding method （such as Turbo code） to lower the threshold of receiver, the influence of MAI can be dropped. The experimental results show that the presented digital watermarking scheme is more secure, and at the same time, keeping the watermarking imperceptible, higher watermarking capacity can be embedded into host image. More important, it is robust against general image processing operations, especially against adding Gaussian noise, geometric distortion （including cropping, horizon moving and rotating）, JPEG glossy compression, filter attacks. Even the watermarked image degraded greatly because of the attacks, the watermarking can be extracted very well.