臺灣博碩士論文加值系統

本篇論文提出了一種植基於離散小波轉換的數位浮水印技術。一靜態影像經小波轉換後，將每個浮水印二元值插入其相對的四分樹的所有重要係數之中。並且引用了以頻率領域為基礎的人類視覺系統的特性，將其結合至浮水印嵌入法之中，以提供最大強度的不可見浮水印。為了使浮水印更強健，我們提出了以下三個方法：(1)定義小波四分樹中的重要係數，(2)可自動調整的適應性臨界值－α ，(3)控制每個子頻帶JND值的權重－γ。
論文中所使用的浮水印是人類視覺所能辨識的二元影像，而非亂數產生的位元序列。因此人眼可輕易地辨識出取回的浮水印。在插入浮水印之前，我們使用了虛擬亂數排列的技術，來預防浮水印被不法竄改，或預防在未經許可的情況之下被攻擊者存取使用。實驗結果顯示本篇論文所提出的方法，能抵抗一般的影像處理以及高壓縮率之JPEG壓縮的破壞。而且取出浮水印的方法既簡單又快速。

This thesis presents a simple and effective DWT-based frequency-domain image watermarking technique. The watermark information is inserted into all significant coefficients of wavelet quadtrees. To provide the maximum strength transparent watermark, the characteristics of the human visual system (HVS) on frequency-domain have been incorporated into the watermark insertion design. For robustness, we proposed three ideas: (1) Significant coefficients of wavelet quadtree, (2) Adaptive threshold, α, and (3) The weight, γ , imposed on the JND value of each subband.
The watermark used is a visually recognizable binary image rather than a randomly generated sequence of bits. Thus, human eyes can easily identify the extracted watermark. Before embedding, the pseudo-random permutation technique is used to prevent the watermark from tampering or unauthorized access by attackers. Experimental results show that the proposed method is resistant to some image-processing operations and JPEG compression with high compression ratio. Moreover, the algorithm for watermark extraction is simple and fast.

Chapter 1 Introduction---------------------------------1
1.1 Motivation-----------------------------------------1
1.2 Digital Watermarking Classification----------------2
1.3 Thesis Organization--------------------------------4
Chapter 2 Background-----------------------------------5
2.1 Structure of A Typical Watermarking System---------5
2.2 Watermarking Requirements--------------------------9
2.3 Watermarking Applications-------------------------12
Chapter 3 Related Techniques--------------------------16
3.1 Watermark Permutation Algorithm-------------------16
3.2 Human Visual System-------------------------------19
3.2.1 The JND on Spatial Domain--------------19
3.2.2 The JND on Frequency Domain------------21
3.3 Discrete Wavelet Transform------------------------22
3.3.1 Quadtrees of Wavelet Coefficients------23
3.3.2 Significant Wavelet Coefficients-------23
3.4 Similarity Measurement----------------------------23
Chapter 4 The Proposed Approach-----------------------25
4.1 Watermark Embedding Algorithm---------------------26
4.2 Watermark Extracting Algorithm--------------------32
4.3 Secret Key----------------------------------------33
Chapter 5 Simulation Results--------------------------34
5.1 JPEG compression----------------------------------36
5.2 Cropping------------------------------------------39
5.3 Noise---------------------------------------------42
5.4 Combined Attacks----------------------------------45
5.5 Other Attacks-------------------------------------47
Chapter 6 Conclusion----------------------------------50
References--------------------------------------------51

[1] B. Schneier, Applied Cryptography, 2nd Edition, John Wiley & Sons, 1996.
[2] D. R. Stinson, Cryptography: Theory and Practice, CRC Press, 1995.
[3] H. Berghel and L. O’Gorman, “Protecting Ownership Rights through Digital Watermarking”, IEEE Computer Mag., pp.101 —103, July 1996.
[4] Mitchell D. Swanson, Mei Kobayashi and Ahmed H. Tewfik, “Multimedia Data-Embedding and Watermarking Technologies”, Proc. IEEE, Vol. 86, pp. 1064 —1087, June 1998.
[5] J. Fridrich, “Methods for Detecting Changes in Digital Images”, Proc. IEEE Int. Workshop on Intell. Signal Processing and Communication Systems, 1998.
[6] D. kundur and D. Hatzinakos, “Digital Watermarking for TellTale Tamper Proofing and Authentication”, Proceedings of the IEEE, Vol. 87, pp. 1167 —1180, 1999.
[7] C. S. Lu, H. Y. Mark Liao and C. J. Sze, “Combined Watermarking for Image Authentication and Protection”, IEEE Int. Conf. on Multimedia and Expo, Vol. 3, pp.1415 —1418, 2000.
[8] C. S. Lu, H. Y. Mark Liao and L. H. Chen, “Multipurpose Audio Watermarking”, Proc. 15th Int. Conf. on Pattern Recognition, Vol. 3, pp.282 —285,2000.
[9] M. M. Yeung and F. Mintzer, “An Invisible Watermarking Technique for Image Verification”, IEEE Conf. Image Processing, Vol. 2, pp.680 —683, 1997.
[10] Fernando Pérez-González and Juan R. Hernández, “A TUTORIAL ON DIGITAL WATERMARKING”, Security Technology, 1999. Proceedings. IEEE 33rd Annual 1999 International Carnahan Conference on, pp.286 —292, 1999.
[11] C. H. Chou and Y. C. Li, “A perceptually tuned subband image coder based on the measure of just-noticeable-distortion profile”, IEEE Trans. Circuits Syst. Video Technol., Vol. 5 no. 6, pp. 467 —476, Dec. 1995.
[12] StirMark 3.1 Watermark Robustness Testing Software (1998). [Online]. (Available: http://www.cl.cam.ac.uk/~fapp2/watermarking/stirmark/)
[13] C. -T. Hsu and J. -L. Wu, “Hidden digital watermarks in images”, IEEE Transactions on Image Processing, Vol. 8, No. 1, pp. 58 —68, 1999.
[14] B. Sklar, Digital Communications: Fundamentals and Applications, Prentice-Hall, 1988.
[15] Christine I. Podilchuk, Member, IEEE, and Wenjun Zeng, “Image-adaptive watermarking using visual models”, IEEE Journal on Selected Areas in Communications, Vol. 16, No. 4, pp. 525 —539, May 1998.
[16] Wen-Nung Lie and Li-Chun Chang, “Spatial-Domain Image Watermarking By Data Embedding At Adaptive Bit Positions”, 12th IPPR Conference on Computer, Vision, Graphics and Image Processing, pp. 16 —21, 1999.
[17] Soo-Chang Pei, Yu-Hau Chen, and Ru-Fang Torng, “Digital Image and Video Watermarking Utilizing Just-Noticeable-Distortion Model”, 12th IPPR Conference on Computer Vision, Graphics and Image Processing, pp. 174 —182, 1999.
[18] Wen-Chu Cheng, Ching-Wen Chu, and Jia-Shung Wang, “A Robust Watermarking Method on Discrete Cosine Transform Domain”, 12th IPPR Conference on Computer Vision, Graphics and Image Processing, pp. 191 —198, 1999.
[19] Chun-Shien Lu, Shih-Kun Huang, Chwen-Jye Sze, and Hong-Yuan Mark Liao, “Cocktail Watermarking for Digital Image Protection”, IEEE Transactions on Multimedia, Vol. 2, No. 4, pp. 209 —224, December, 2000.
[20] A. B. Watson, G. Y. Yang, J. A. Solomon, and J. Villasenor, “ Visibility of wavelet quantization noise”, IEEE Trans. Image Processing, Vol. 6, pp. 1164 —1175, 1997.
[21] A. R. Calderbank, Ingrid Daubechies, Wim Sweldens, and Boon-Lock Yeo, “Wavelet transforms that map integers to intergers”, Journal of Applied and Computational Harmonic Analysis (ACHA), Vol. 5, No. 3, pp. 322 —369, 1998.
[22] H. Inoue, A. Miyazaki, A. Yamamoto and T. Katsura, “A digital watermark based on the wavelet transform and its robustness on image compression”, ICIP 98, Proceedings, Vol. 2, pp.391 —395, 1998.
[23] C. -T. Hsu and J. -L. Wu, “Hidden signatures in images”, in Proceedings ICIP’96, pp. 223 —226, 1996.
[24] Shinfeng D. Lin and Chin-Feng Chen, “A Robust DCT-based Watermarking for Copyright Protection”, Consumer Electronics, IEEE Transactions on, Vol. 46 Issue: 3, p. 415 —421, Aug. 2000.