迭加与量化水印嵌入方案的比较及量化参数优化

Performance Comparison of Two Watermark Embedding Techniques and Optimization of QIM Parameters

分别研究了迭加法和量化法的隐蔽性和稳健性,并且提出了量化调制水印方案中的参数优化方法。对两类方法的分析比较表明,迭加法适用于在高频分量嵌入水印,而量化法适用于在低频分量嵌入水印。并以实验验证了这一结论。

A parameter-optimized method based on quantination index modulation (QIM), which chooses an appropriate quantization step and an optimal length of watermark sequence leading to maximal robustness under a given embedding-induced PSNR, was presented. Imperceptibility and robustness of the two watermark embedding techniques, namely addition of PN sequence and optimized QIM, were compared. Theoretical analysis and numerical experiments show that the method of addition is suitable for watermark embedding into high frequency components, whereas the optimized QIM is more appropriate for embedding into low frequency components.