基于扩频和量化的混合水印研究

扩频和量化技术是数字水印中2种基本的技术,扩频水印有鲁棒性强的特点,而量化水印具有更大的容量.考虑到两者之间存在互补性,构造一种组合扩频和量化技术的混合模型,以实现在水印鲁棒性的前提下达到水印容量最大化的目的,并通过理论分析给出了扩频长度、信道容量和检测错误率等参数之间的相互关系.在多小波变换域内的实验结果表明,所提出的算法既具有较高的嵌入容量,又具有较强的鲁棒性.

Hybrid watermarking algorithm based on spread spectrum and quantization

Spread spectrum and quantization are two basic techniques of digital watermarking.Spread spectrum watermarking is known to be robust against attack and quantization watermarking allows a higher capacity.Considering the complementary characteristics of both techniques,a hybrid watermarking model was constructed by integrating spread spectrum and quantization techniques to maximize watermark capacity under the precondition of robustness.Moreover,performance analysis was used to describe the interrelations among spread spectrum code length,channel capability,detection error rate,and other factors.In multiwavelet domain,the experimental results demonstrate that the proposed algorithm provides higher embedding capacity as well as more robustness against attack.