数字水印系统的信噪比估算

Signal-to-Noise Ratio Estimation for Watermarking System

在网络化的环境中,数字水印技术作为多媒体数据版权保护问题的一种解决方法被提了出来。为了保持被保护多媒体数据的质量,水印必须是感觉上不可见的。也就是说,作为一种失真测度,加入水印后的多媒体数据的信噪比必须高于一规定门限。在文中,考虑了空间域水印算法和频率域水印算法的特点,分别推导了对应的水印系统信噪比估算公式。理论分析表明,系统信噪比与多媒体数据本身无关。对于设计一个实际的水印系统,论文的结论是非常有用的。

Digital watermarking has been proposed as a solution to the problem of copyright protection of multimedia data in a networked environment.In order to preserve the quality of multimedia data,the watermark should be perceptually invisible.In other words,the signal-to-noise ratio of watermarked multimedia data must be higher than a prescribed threshold as a distortion measure.In this paper,we consider the characteristics of algorithms based on spatial domain and frequency domain ,the corresponding estimation formulas of signal-to-noise ratio of watermarking system are derived respectively.Theoretical analysis indicates that signal-to-noise ratio of system is independent of multimedia data themselves.These results are useful during designing a practical watermarking system.