基于DWT-DCT的灰度图像数字水印算法.doc

文档介绍：
基于 DWT-DCT 的灰度图像数字水印算法#
张元钦1,2,马兆丰1,2,辛阳1,3**
(1. 北京邮电大学信息安全中心,北京 100876;
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2. 北京国泰信安科技有限公司,北京 100086;
3. 北京安码科技有限公司,北京 100082)
摘要:图像数字水印在图像防伪领域有了很广泛的应用。本文针对灰度载体图像,在现有的
DWT、DCT 算法基础上,提出 DWT、DCT 同时使用的嵌入和提取水印算法。通过将灰度
图像经过一级 DWT 后的 HL1 域进行 DCT 变换,再改变 DCT 中频系数以嵌入水印信息。
最后实验表明,该算法在保持较高峰值信噪比的前提下,对随机噪声,椒盐噪声,都有良好
的抵抗效果。
关键词:灰度图像;数字水印;DWT;DCT
中图分类号:TP391
The digital watermarking algorithm of grayscale image
based on DWT-DCT
Zhang Yuanqin1,2, Ma Zhaofeng1,2, Xin Yang1,3
(1. Information Security Center, Beijing University of Posts and munications,
Beijing 100876;
2. Beijing National Security Science and Technology Co. Ltd, Beijing 100086;
3. Beijing Safe-Code Technology , Beijing 100082)
Abstract: Image watermarking has a very wide range of application in the field of image
authentication. In this paper, a new digital watermarking algorithm based on DWT and DCT is
proposed plete watermark embedding and extraction program in grayscale image. By
applying DWT transform in host image and then DCT transform in HL1 area, watermark
information can be embedded in intermediate frequency coefficients. Final experiments show that
the algorithm has strong resistance effect to random noise, salt and pepper noise.
Keywords: grayscale image; digital watermark; Discrete Wavelet Transform (DWT) ; Discrete
Cosine Transform (DCT)
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0 引言
随着多媒体技术的进一步发展,复