基于变换域的数字水印技术研究
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摘要
网络技术的发展使得网络传输的数字产品在没有授权的情况下容易被有恶意的人们随意篡改、拷贝。近几年来提出的数字水印技术可以解决这个问题。虽然研究者们为研究该项技术付出了大量的精力，并取得了一定的成果，但是数字水印技术的研究正处在起步阶段，还存在许多问题，这限制了它的应用。
本文从三个不同的角度来研究数字水印技术，其目的是在保证不可见性的前提下，提高数字水印的鲁棒性。主要完成以下工作：
(1)本文利用混沌系统和离散柯尔莫哥罗夫变换，提出两种水印序列生成算法。该算法安全性好，且生成的水印序列均值近似于零，为后面两种水印技术做准备。
(2)提出一种基于离散余弦变换(DCT)的自适应水印技术。该技术首先采用边缘检测方法确定边缘块；根据DCT系数方差确定纹理块；然后根据人的视觉特性把图像的DCT块分成六类。不同强度的水印成分自适应地嵌入在低频域系数上，保证了水印抗攻击鲁棒性。实验结果表明此方法比同类方法要好。
(3)提出一种基于离散小波变换(DWT)的公有水印技术。该技术在公
广西大学硕士论文
基于变换域的数字水印技术研究
有水印模型中引入了混沌系统，水印嵌入在DWT域的低频系数，并且在
水印嵌入时引入一个指数因子，本文对使用不同指数因子嵌入的水印抗
攻击鲁棒性进行了实验分析，实验结果表明:指数因子在0.1一0.2之间
的水印鲁棒性要更好些。
With the development of network technology, the digital products transmitted through the Internet are easier to be modified or copied by vicious people at will without authorization. The digital watermarking technology was presented several years ago to resolve this problem. Though researchers pay out a mass of vigor for this technology and acquire some achievements, the digital watermarking technology is still on road to development and many existing problems hold back its application.
The digital watermarking technology is studied from three different points of view to improve the robustness under the precondition of invisibility. The primary contributions of this paper contain the following points:
(1) Two algorithms are presented using chaotic system and discrete Kolmogorov flows to create watermark sequences .The algorithms have good security and the mean of watermark sequences is close to zero, preparing for following two algorithms.
(2) The proposed method is an adaptive watermarking technology based on Discrete Cosine Transformation (DCT). This method discerns the edge blocks using the edge detection method and texture blocks using the deviations of DCT coefficients at first, and then the DCT blocks of image are classified into 6 blocks based on Human Visual System (HVS). Watermark components with different strengths are adaptively embeded into some low-frequency coefficients according to the classification to ensure good robustness against attacks. The experimental results show this algorithm possesses better robustness than the similar algorithms.
(3) A public watermarking technology based on Discrete Wavelet Transformation (DWT) is proposed, which introduces Chaos systems into the modified public watermarking model. The watermark is embedded into the low-frequency coefficients of
DWT domain and an index factor is used in this technology. In the experiment, this paper analyses the robustness of watermark against attacks using the different index factors and concludes when the value of the index factor is between 0.1 and 0.2,the robustness of watermark against attacks is better.
本文从三个不同的角度来研究数字水印技术，其目的是在保证不可见性的前提下，提高数字水印的鲁棒性。主要完成以下工作：
(1)本文利用混沌系统和离散柯尔莫哥罗夫变换，提出两种水印序列生成算法。该算法安全性好，且生成的水印序列均值近似于零，为后面两种水印技术做准备。
(2)提出一种基于离散余弦变换(DCT)的自适应水印技术。该技术首先采用边缘检测方法确定边缘块；根据DCT系数方差确定纹理块；然后根据人的视觉特性把图像的DCT块分成六类。不同强度的水印成分自适应地嵌入在低频域系数上，保证了水印抗攻击鲁棒性。实验结果表明此方法比同类方法要好。
(3)提出一种基于离散小波变换(DWT)的公有水印技术。该技术在公
广西大学硕士论文
基于变换域的数字水印技术研究
有水印模型中引入了混沌系统，水印嵌入在DWT域的低频系数，并且在
水印嵌入时引入一个指数因子，本文对使用不同指数因子嵌入的水印抗
攻击鲁棒性进行了实验分析，实验结果表明:指数因子在0.1一0.2之间
的水印鲁棒性要更好些。
With the development of network technology, the digital products transmitted through the Internet are easier to be modified or copied by vicious people at will without authorization. The digital watermarking technology was presented several years ago to resolve this problem. Though researchers pay out a mass of vigor for this technology and acquire some achievements, the digital watermarking technology is still on road to development and many existing problems hold back its application.
The digital watermarking technology is studied from three different points of view to improve the robustness under the precondition of invisibility. The primary contributions of this paper contain the following points:
(1) Two algorithms are presented using chaotic system and discrete Kolmogorov flows to create watermark sequences .The algorithms have good security and the mean of watermark sequences is close to zero, preparing for following two algorithms.
(2) The proposed method is an adaptive watermarking technology based on Discrete Cosine Transformation (DCT). This method discerns the edge blocks using the edge detection method and texture blocks using the deviations of DCT coefficients at first, and then the DCT blocks of image are classified into 6 blocks based on Human Visual System (HVS). Watermark components with different strengths are adaptively embeded into some low-frequency coefficients according to the classification to ensure good robustness against attacks. The experimental results show this algorithm possesses better robustness than the similar algorithms.
(3) A public watermarking technology based on Discrete Wavelet Transformation (DWT) is proposed, which introduces Chaos systems into the modified public watermarking model. The watermark is embedded into the low-frequency coefficients of
DWT domain and an index factor is used in this technology. In the experiment, this paper analyses the robustness of watermark against attacks using the different index factors and concludes when the value of the index factor is between 0.1 and 0.2,the robustness of watermark against attacks is better.
引文
[1] 黄继武，图像隐形水印：现状和未来，第八届全国多媒体技术学术会议，1999，10：394-399．
[2] Van Schyndel R.G, Tirkel A.Z,Osborn,A digital watermarking,Int,Conference on Image Processing,Austin,Texas,USA, 1994IEEE,2: 86-90.
[3] Wolfgong P, Delp E, A watermarking for digital images, Proc.IEEE Internet Conf.Image Processing' 96,Sept. 16-19,1996: 219-222.
[4] W.Bender,D.Gruhl,N.Morimoto,Techniques for Data Hidding,in Proc.SPIE, Vol.2420, San Jose,CA, 1995,2: 40-44.
[5] I.Pitas,A Method for Signature Casting on digital Images, [DB/OL].http://clip.informatik.uni-leipzig.de/～toelke/Watermark/1498.pdf
[6] Chang-Hsing Lee,Yeuan-Kuen Lee,An Adaptive Digital Image Watermarking Technique for Copyright Protection. [DB/OL].http://debut.cis.nctu.edu.tw/pages/publish/IS99-Watermarking.pdf
[7] Ingemar J. Cox, Joe Kilian, Tom Leighton et al. Secure Spread Spectrum Watermarking for Multimedia[J]. IEEE Transaction on Image Processing, 1997,12(6): 1673～1687.
[8] Ingemar J. Cox, Joe Kilian, Tom Leighton et al. Secure Spread Spectrum Watermarking for Multimedia[R]. NEC Research Institute,Tech Rep, 1995,10: 1-33.
[9] E.Koch,J.Rindfrey, J.zhao,Copyright protection for multimedia data, [DB/OL].http://citeseer.ist.psu.edu/context/43326/0
[10] A.G.Bors,I.Pitas,Image watermarking using DCT domain constraints,Proc.of ICIP'96, 1996, 3: 231-234.
[11] A.piva,M.Bami,F.Baolini, V.Cappellini,DCT-based watermark recovering without resorting to the uncorrupted original image,Proc.of ICIP'97,1997, 3: 520-523,.
[12] M.Ramkumar, A.N.Akansu,A.Alatan,A robust data hiding scheme for images using DFT, in Proceedings of the 6th IEEE International Conference on Image Processing ICIP'99(Kobe,Japan), 1999,8: 211-215.
[13] 伯晓晨，沈林成，常文森，一种新的盲图像水印检测算法，计算机学报，2001，24(12)：1279-1286．
[14] Hisahi Inoue,Akio Miyazaki,Takashi Katsura,Adigital watermark for images using the wavelet transform, Integrated Computer-Aided Engineering 2000,7: 105-115.
[15] C.I.Podilchuk, Wenjun Zeng,Image-adaptive watermarking using visual models,IEEE Journal on
Selected Areas in Communications, 1998, 16(4): 525-539.
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[18] A.S.Lewis,G.Knowles,Image compression using the 2-D wavelet transform,IEEE Trans. Image Processing 1992,1: 244-250.
[19] D.Kundur, D.Hatzinakos,A Robust Digital Image Watermarking Method using Wavelet-Based Fusion. [DB/OL]. ee.tamu.edu/～deepa/pdf/icip97a.pdf
[20] M.D.Levine,Vision in Man and Machine,McGraw-Hill,Toronto, 1985.
[21] I．J．Cox,M．L．Miller,J．A．Bloom编，王颖，黄志蓓等译，数字水印，电子工业出版社，2003，7．
[22] S．Katzenbeisser，Fabien A．P．Petitcolas编，吴秋新，钮心忻等译，信息隐藏技术—隐写术与数字水印，人民邮电出版社，2001，9．
[23] 吕金虎，陆君安，陈士华，混沌时间序列分析及其应用，武汉大学出版社，2002，1．
[24] 易开祥，数字图像加密与数字水印技术研究[博士学位论文]，杭州：浙江大学，2001．
[25] L.boney, A.H.Tewfik,K.N.Hamdy, Digital Watermarks for Audio Signals,IEEE Intemational Conference on Multimedia Computing and Systems,Hiroshima,Japan, 17-23 June 1996: 473-480
[26] F. Hartung, B.Girod,Watermarking of MPEG-2 encoded video without decoding and re-encoding, Multimedia Computing and Networking 1997,published as SPIE 3020: 264-273
[27] 易开祥，孙鑫，石教英，一种基于混沌序列的图像加密算法，计算机辅助设计与图形学报，2000，12(9)：672-676
[28] 王毅，基于混沌序列的图像加密研究，计算机工程与应用，2002，20：99-102
[29] 王慧琴，李人厚，王志雄，基于混沌加密的频率域数字图像水印算法，计算机应用研究，2002，1：71-73．
[30] T.Kohda,A.Tsuneda,Chaotic Bit Sequences for Stream Cipher Cyptography and Their Correlation Properties,IEICE Trans.Commun, SPIE2612, 1995.
[31] 唐秋玲，覃团发，陈光旨，混沌图像加密，广西大学学报(自然科学版)，1999，24(1)：61-64．
[32] 齐东旭，邹建成，韩效宥，一类新的置乱变换及其在图像信息隐蔽中的应用，中国科学(E辑)，2000，30(5)：440-447．
[33] 丁玮，齐东旭，数字图像变换及信息隐藏与伪装技术，计算机学报，1998，12(9)：838-843．
[34] 丁玮，闫伟齐，齐东旭，基于Arnold变换的数字图像置乱技术[J]，计算机辅助设计与图形学报，2001，13(4)：338-341．
[35] 丁玮，闫伟齐，齐东旭，基于生命游戏的数字图像置乱与数字水印技术，北方工业大学学报，2000，
12(1)：1-5．
[36] 丁玮，闫伟齐，齐东旭，基于置乱与融合的数字图像隐藏技术及其应用，中国图像图形学报，2000，5(A)(8)：644-649．
[37] 吴旻升，王介生，刘慎权，图像的排列变换，计算机学报，1998，21(6)：514-519
[38] J. Scharinger, Secure digital watermark genertion based on chaotic Kolmogorov flows, in Security and Watermarking of Multimedia Content Ⅱ,Proceedings of SPIE Vol.3971, 2000: 306-313.
[39] T.D.Tran,A Locally Adaptive Perceptual Masking Threshold Model for Image Coding[Dissertation],Massachusetts institute of technology, 1994.
[40] 黄继武,YunQ．Shi,姚若河，基于块分类的自适应图像水印算法，中国图像图形学报，1999，4(A版)(8)：640-643．
[41] 黄继武,Yun Q．Shi，一种自适应图像水印算法，自动化学报，1999，25(4)：476-482．
[42] 钟伟，余松煜，马希俊，基于分块DCT的自适应水印算法，红外与激光工程，2000，29(5)：22-26．
[43] 汪春生，程义民，王以孝，一种基于块分类的图像水印算法，微型机与应用，2002，6：54-57．
[44] 易开祥，石教英，自适应二维数字水印系统，中国图像图形学报，2001，6(A版)(5)：444-449．
[45] 茅耀斌，卓成春，王执铨，戴跃伟，一种基于人眼视觉特性的图像水印方案，厦门大学学报(自然科学版)，2001，40(增刊1)：232-235．
[46] 刘炎，施鹏飞，一种基于HVS的数字水印算法，计算机工程与应用，2001，17：133-139．
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[50] I.J.Cox, Joe Kilian.Tom Leightont and Talal Shamoom, A Secure Robust Watermark for Multimedia, Workshop on Information Hiding. Newton Institute Univ. of Cambridge, 1996,5: 185-206.
[51] Alessandra Lumini, Dario Maio, A blind watermarking system for digital images in the wavelet domain[C].Security and Watermarking of Multimedia content Ⅱ. Proceedings of SPIE3971, 2000: 524-535
[52] Mauro Barni, Franco Bartolini,Vito Cappellini, Alessandro Piva, A DCT-domain system for robust image watermarking[J].Signal Processing 1998,(66): 357～372
[53] Rakesh Dugad, Krishna Ratakonda, Narendra Ahuja. A New Wavelet-Based Scheme for Watermarking Images.
[DB/OL].http://citeseer.nj.nec.com/cache/papers/cs/13277/http:zSzzSzclip.informatik.uni-leipzig. dezSztoelkezSzWatermarkzSzta10_07.pdf/a-new-wavelet-based.pdf
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[55] Hisashi Inouea,Akio Miyazakib,Takashi Katsuraa, A digital watermark for images using the wavelet transform[J]. Integrated Computer-Aided Engineering, 2000,7: 105～115
[56] M.Barni,F.Bartolini,V.Cappellini,A.Lippi,A.Piva,A DWT-based technique for spatio-frequency masking of digital signatures[DB/OL].http://citeseer.nj.nec.com/cache/papers/cs/1082/http:zSzzSzlci.die.unifi.itzSzPublications zSzswmc99-04.pdf/barni99dwtbased.pdf
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[58] 崔晓瑜，数字水印技术的研究[博士学位论文]，北京：北京大学，2001．
[2] Van Schyndel R.G, Tirkel A.Z,Osborn,A digital watermarking,Int,Conference on Image Processing,Austin,Texas,USA, 1994IEEE,2: 86-90.
[3] Wolfgong P, Delp E, A watermarking for digital images, Proc.IEEE Internet Conf.Image Processing' 96,Sept. 16-19,1996: 219-222.
[4] W.Bender,D.Gruhl,N.Morimoto,Techniques for Data Hidding,in Proc.SPIE, Vol.2420, San Jose,CA, 1995,2: 40-44.
[5] I.Pitas,A Method for Signature Casting on digital Images, [DB/OL].http://clip.informatik.uni-leipzig.de/～toelke/Watermark/1498.pdf
[6] Chang-Hsing Lee,Yeuan-Kuen Lee,An Adaptive Digital Image Watermarking Technique for Copyright Protection. [DB/OL].http://debut.cis.nctu.edu.tw/pages/publish/IS99-Watermarking.pdf
[7] Ingemar J. Cox, Joe Kilian, Tom Leighton et al. Secure Spread Spectrum Watermarking for Multimedia[J]. IEEE Transaction on Image Processing, 1997,12(6): 1673～1687.
[8] Ingemar J. Cox, Joe Kilian, Tom Leighton et al. Secure Spread Spectrum Watermarking for Multimedia[R]. NEC Research Institute,Tech Rep, 1995,10: 1-33.
[9] E.Koch,J.Rindfrey, J.zhao,Copyright protection for multimedia data, [DB/OL].http://citeseer.ist.psu.edu/context/43326/0
[10] A.G.Bors,I.Pitas,Image watermarking using DCT domain constraints,Proc.of ICIP'96, 1996, 3: 231-234.
[11] A.piva,M.Bami,F.Baolini, V.Cappellini,DCT-based watermark recovering without resorting to the uncorrupted original image,Proc.of ICIP'97,1997, 3: 520-523,.
[12] M.Ramkumar, A.N.Akansu,A.Alatan,A robust data hiding scheme for images using DFT, in Proceedings of the 6th IEEE International Conference on Image Processing ICIP'99(Kobe,Japan), 1999,8: 211-215.
[13] 伯晓晨，沈林成，常文森，一种新的盲图像水印检测算法，计算机学报，2001，24(12)：1279-1286．
[14] Hisahi Inoue,Akio Miyazaki,Takashi Katsura,Adigital watermark for images using the wavelet transform, Integrated Computer-Aided Engineering 2000,7: 105-115.
[15] C.I.Podilchuk, Wenjun Zeng,Image-adaptive watermarking using visual models,IEEE Journal on
Selected Areas in Communications, 1998, 16(4): 525-539.
[16] J.J.chae and B.S.Man Junath,A Robust Embedded Data from Wavelet Coefficients, [DB/OL] .vision.ece.ucsb.edu/publications/98 SPIE.pdf
[17] M.Barni,F.Bartolini,V.Cappellini et.al,A DWT-based technique for spatio-frequency masking of digital signatures. [DB/OL].citeseer.ist.psu.edu/barni99dwtbased.html.
[18] A.S.Lewis,G.Knowles,Image compression using the 2-D wavelet transform,IEEE Trans. Image Processing 1992,1: 244-250.
[19] D.Kundur, D.Hatzinakos,A Robust Digital Image Watermarking Method using Wavelet-Based Fusion. [DB/OL]. ee.tamu.edu/～deepa/pdf/icip97a.pdf
[20] M.D.Levine,Vision in Man and Machine,McGraw-Hill,Toronto, 1985.
[21] I．J．Cox,M．L．Miller,J．A．Bloom编，王颖，黄志蓓等译，数字水印，电子工业出版社，2003，7．
[22] S．Katzenbeisser，Fabien A．P．Petitcolas编，吴秋新，钮心忻等译，信息隐藏技术—隐写术与数字水印，人民邮电出版社，2001，9．
[23] 吕金虎，陆君安，陈士华，混沌时间序列分析及其应用，武汉大学出版社，2002，1．
[24] 易开祥，数字图像加密与数字水印技术研究[博士学位论文]，杭州：浙江大学，2001．
[25] L.boney, A.H.Tewfik,K.N.Hamdy, Digital Watermarks for Audio Signals,IEEE Intemational Conference on Multimedia Computing and Systems,Hiroshima,Japan, 17-23 June 1996: 473-480
[26] F. Hartung, B.Girod,Watermarking of MPEG-2 encoded video without decoding and re-encoding, Multimedia Computing and Networking 1997,published as SPIE 3020: 264-273
[27] 易开祥，孙鑫，石教英，一种基于混沌序列的图像加密算法，计算机辅助设计与图形学报，2000，12(9)：672-676
[28] 王毅，基于混沌序列的图像加密研究，计算机工程与应用，2002，20：99-102
[29] 王慧琴，李人厚，王志雄，基于混沌加密的频率域数字图像水印算法，计算机应用研究，2002，1：71-73．
[30] T.Kohda,A.Tsuneda,Chaotic Bit Sequences for Stream Cipher Cyptography and Their Correlation Properties,IEICE Trans.Commun, SPIE2612, 1995.
[31] 唐秋玲，覃团发，陈光旨，混沌图像加密，广西大学学报(自然科学版)，1999，24(1)：61-64．
[32] 齐东旭，邹建成，韩效宥，一类新的置乱变换及其在图像信息隐蔽中的应用，中国科学(E辑)，2000，30(5)：440-447．
[33] 丁玮，齐东旭，数字图像变换及信息隐藏与伪装技术，计算机学报，1998，12(9)：838-843．
[34] 丁玮，闫伟齐，齐东旭，基于Arnold变换的数字图像置乱技术[J]，计算机辅助设计与图形学报，2001，13(4)：338-341．
[35] 丁玮，闫伟齐，齐东旭，基于生命游戏的数字图像置乱与数字水印技术，北方工业大学学报，2000，
12(1)：1-5．
[36] 丁玮，闫伟齐，齐东旭，基于置乱与融合的数字图像隐藏技术及其应用，中国图像图形学报，2000，5(A)(8)：644-649．
[37] 吴旻升，王介生，刘慎权，图像的排列变换，计算机学报，1998，21(6)：514-519
[38] J. Scharinger, Secure digital watermark genertion based on chaotic Kolmogorov flows, in Security and Watermarking of Multimedia Content Ⅱ,Proceedings of SPIE Vol.3971, 2000: 306-313.
[39] T.D.Tran,A Locally Adaptive Perceptual Masking Threshold Model for Image Coding[Dissertation],Massachusetts institute of technology, 1994.
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