Evaluation of the Image Degradation for a Typical Watermarking Algorithm in the Block-DCT Domain
Evaluation of the Image Degradation for a Typical Watermarking Algorithm in the Block-DCT Domain
复制标题
块-DCT 域中典型水印算法的图像劣化评估
DOI：
10.1007/3-540-45600-7_7
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Wensen Chang
中科院分区：
文献类型：
--
作者：
Xiaochen Bo;Lincheng Shen;Wensen Chang
数字水印是保护数字媒体知识产权的一项关键技术。近年来，针对各种应用，提出了许多在图像中嵌入水印的方法，对水印算法的评估变得越来越重要。水印图像的劣化程度可以通过信噪比（SNR）或峰值信噪比（PSNR）来衡量，是水印算法的主要性能指标之一。本文基于DCT系数的拉普拉斯分布模型，推导了典型水印算法中的缩放参数与水印图像退化之间的理论关系。实验结果表明，SNR和PSNR的估计误差均小于1 dB。利用这种关系，我们设计了一种自适应插入策略，可用于在指定 SNR 或 PSNR 的自然图像中嵌入水印。
Digital watermarking is a key technique for protecting intellectual property of digital media. As a number of methods have been proposed in recent years to embed watermarks in images for various applications, evaluation of watermarking algorithms becomes more and more important. The degradation of watermarked images, which can be measured by signal to noise ratio (SNR) or peak signal to noise ratio (PSNR), is one of the major performance indexes of watermarking algorithms. In this paper, based on the Laplacian distribution model of DCT coefficients, we deduce a theoretical relationship between the scaling parameter in a typical watermarking algorithm and the degradation of watermarked images. Experimental results show that the estimation error of SNR and PSNR is less than 1 dB. Using this relationship, we design an adaptive insertion strategy that can be employed to embed watermarks in natural images with assigned SNR or PSNR.