Statistical amplitude scale estimation for quantization-based watermarking
Statistical amplitude scale estimation for quantization-based watermarking
复制标题
DOI：
10.1117/12.526432
复制
发表时间：
2004-06
期刊：
影响因子：
--
通讯作者：
Ivo D. Shterev;R. Lagendijk;R. Heusdens
中科院分区：
文献类型：
--
作者：
Ivo D. Shterev;R. Lagendijk;R. Heusdens
基于量化的水印方案容易受到幅度缩放的影响。因此，在水印解码之前，必须在编码器或解码器处考虑比例因子。本文推导了当攻击信道由幅度缩放和加性噪声组成时，水印和攻击数据的边际概率密度模型。编码器采用带失真补偿的量化指标调制。在此模型的基础上，我们得到了尺度参数的两种估计方法。第一种方法是基于概率密度函数的傅立叶分析。尺度参数的估计依赖于接收数据的结构。我们得到的第二种方法是比例因子的极大似然估计。我们从理论上和实验上对真实音频信号的估计过程进行了研究，并将其与文献中其他已知的幅度尺度估计方法进行了比较。
Quantization-based watermarking schemes are vulnerable to amplitude scaling. Therefore the scaling factor has to be accounted for either at the encoder, or at the decoder, prior to watermark decoding. In this paper we derive the marginal probability density model for the watermarked and attacked data, when the attack channel consists of amplitude scaling followed by additive noise. The encoder is Quantization Index Modulation with Distortion Compensation. Based on this model we obtain two estimation procedures for the scale parameter. The first approach is based on Fourier Analysis of the probability density function. The estimation of the scaling parameter relies on the structure of the received data. The second approach that we obtain is the Maximum Likelihood estimator of the scaling factor. We study the performance of the estimation procedures theoretically and experimentally with real audio signals, and compare them to other well known approaches for amplitude scale estimation in the literature.