Computer Engineering and Applications ›› 2010, Vol. 46 ›› Issue (5): 76-79.DOI: 10.3778/j.issn.1002-8331.2010.05.023

• 网络、通信、安全 • Previous Articles     Next Articles

Robust image watermarking algorithm in Hadamard domain

ZHANG Da-xing1,2,LI He-ming1,LI Hai-hua1   

  1. 1.Institute of Graphics and Image,Hangzhou Dianzi University,Hangzhou 310018,China
    2.State Key Lab of CAD & CG,Zhejiang University,Hangzhou 310027,China
  • Received:2008-08-20 Revised:2008-12-25 Online:2010-02-11 Published:2010-02-11
  • Contact: ZHANG Da-xing



  1. 1.杭州电子科技大学 图形图像研究所,杭州 310018
    2.浙江大学 CAD & CG国家重点实验室,杭州 310027
  • 通讯作者: 张大兴

Abstract: This paper proposes a new robust watermarking algorithm based on block Hadamard Transform(HT).The binary watermark image is displaced to destroy space relativity and then expanded to get watermark sequence.The original image is subdivi-
ded to 8×8 blocks and is executed HT transform.Then middle HT coefficients are selected to hide watermark.The correlation of watermark code and the difference of HT coefficients between embedded and original image is used to determine each bit when watermark is detected.Experiment shows that the algorithm has no appreciable influence to image appearance and it is robust to JPEG compression,clipping,filtering and noise pollution.

Key words: digital watermark, Hadamard transform, robust watermark

摘要: 提出了一种基于分块Hadamard变换的鲁棒图像水印算法。水印图像先进行置乱和扩展得到水印序列。原始图像进行8×8分块的Hadamard变换,在中频系数里按不同强度嵌入水印。水印提取时,先计算与原始图像在对应的变换域系数的差值,再计算该差值与水印编码的相关性来确定每个水印像素。实验表明,该算法对原始图像的视觉影响小,具有良好的鲁棒性。

关键词: 数字水印, Hadamard变换, 鲁棒水印

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