EM Estimation of Scale Factor for Quantization-Based Audio Watermarking
EM Estimation of Scale Factor for Quantization-Based Audio Watermarking
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DOI：
10.1007/978-3-540-24624-4_24
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发表时间：
2003-10
期刊：
影响因子：
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通讯作者：
Kiryung Lee;Dong Sik Kim;Taejeong Kim;Kyung-Ae Moon
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文献类型：
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作者：
Kiryung Lee;Dong Sik Kim;Taejeong Kim;Kyung-Ae Moon
盲水印方案提取嵌入的消息而不访问宿主信号。最近，提出了有效的盲水印方案，其利用编码器处的宿主信号的知识[1，2，3]。标量量化器用于实际实现。即使标量量化器可以提供简单的编码和解码方案，如果加水印的信号被缩放，则解码器处的量化器步长应当相应地缩放以用于可靠的解码。在本文中，我们提出了一个预处理的解码方案，它使用一个估计的比例因子。通过高斯混合模型近似接收信号密度，然后通过采用期望最大化算法估计比例因子[6]。在所提出的方案中，比例因子是从接收信号本身估计的，而没有任何额外的导频信号。数值结果表明，该方案提供了一个可靠的解码从缩放信号。
The blind watermarking scheme extracts the embedded message without access to the host signal. Recently, efficient blind watermarking schemes, which exploit the knowledge of the host signal at the encoder, are proposed [1,2,3]. Scalar quantizers are employed for practical implementation. Even though the scalar quantizer can provide simple encoding and decoding schemes, if the watermarked signal is scaled, then the quantizer step size at the decoder should be scaled accordingly for a reliable decoding. In this paper, we propose a preprocessed decoding scheme, which uses an estimated scale factor. The received signal density is approximated by a Gaussian mixture model, and the scale factor is then estimated by employing the expectation maximization algorithm [6]. In the proposed scheme, the scale factor is estimated from the received signal itself without any additional pilot signal. Numerical results show that the proposed scheme provides a reliable decoding from the scaled signal.