摘要

在網路以及消費性電子產品蓬勃發展之後，數位資料的智慧財產權保護以及所有權的認證問題逐漸受到重視，為了解決這些問題許多方法被提出，而數位浮水印系統便是其中之一。
在本篇中，我們使用四種不同的離散小波轉換來實現數位浮水印系統，分別是Haar, Daubechies’ four, 5/3以及9/7 小波轉換。我們藉由取樣常態分佈的亂數來產生浮水印，並將浮水印嵌入在影像經過小波轉換後係數上，我們選擇轉換後的中頻係數做為嵌入的目標。經由一些實驗，包含：縮放、中值濾波、切割、平滑處理、雜訊、JPEG壓縮以及多重浮水印後，顯示我們的方法達到一定程度的隱蔽性及強韌性。

The problem of copyright protection and ownership identification is attention-getting because the Internet applications and consumer electronics products have been rapidly developed. The watermarking system can partially solve this problem. In this thesis, experiments of a watermarking system using 4 different discrete wavelet transforms were implemented. An authorized watermark, sampled from a standard normal distribution, is embedded into the wavelet coefficients of high-low and low-high subbands at level 3 of a 3-scale discrete wavelet transform. Four popular wavelet bases including Haar, Daubechies’ four, 5/3 and 9/7 are chosen for experiments. Our experiments, including scaling, median filtering, cropping, smoothing, noise adding, JPEG compression and multiple watermarks, demonstrate that our watermarking scheme satisfies fidelity, robustness, and security at a certain level.

[Bao2005] P. Bao and X. Ma, “Image adaptive watermarking using wavelet domain singular value decomposition,” IEEE Transactions on Circuits and Systems for Video Technology, Vol. 15, No. 1, 96-102, 2005.
[Chen2002] C.C. Chen, “Watermarking Experiments Based on Wavelet Transforms,” The Proceedings of SPIE: Int'l Conference on Electronic Imaging and Multimedia Technology III, Vol. 4925, 60-68, 2002.
[Chen2006] C.M. Chen, C.C. Chen, and C.C. Chen, “A Comparison of Texture Features Based On SVM and SOM,” International Conference on Pattern Recognition, Vol. 2, 630-633, 2006.
[Chou2003] Y.H. Chou, “A Study on Watermarking Experiments by Wavelet Transforms,” M.S. Thesis, National Tsing Hua University, Taiwan, 2003.
[Cox1997] I.J. Cox, J. Kilian, F.T. Leighton, and T. Shamoon, “Secure spread spectrum watermarking for multimedia,” IEEE Transactions on Image Processing, Vol. 6, No. 12, 1673-1687, 1997.
[Cox2008] I.J. Cox, M.L. Miller, J.A. Bloom, J. Fridirich, T. Kalker, “Digital Watermarking and Steganography,” Morgan Kaufmann Publish, 2008.
[Duga1998] R. Dugad, K. Ratakonda, and N. Ahuja, “A new wavelet-based scheme for watermarking images,” International Conference on Image Processing, Vol. 2, No. 3, 419-423, 1998.
[Hogg2005] R.V. Hogg and E.A. Tanis, “Probability and Statistical Inference”, Prentice Hall, New Jersey, 2005.

[Kim1999] J.R. Kim and Y.S. Moon, “A Robust Wavelet-Based Digital Watermarking Using Level-Adaptive Thresholding,” International Conference on Image Processing, Vol. 2, 226-230, 1999.
[Kun1998] D. Kundur and D. Hatzinakos, “Digital watermarking using multiresolution wavelet decomposition,” International Conference on Acoustics, Speech and Signal Processing, Vol. 5, 2969-2972, 1998.
[Kutt1999] M. Kutter, “Performance Improvement of Spread Spectrum Based Image Watermarking Schemes through M-ary Modulation,” Lecture Notes in Computer Science, Vol. 1728, 238-250, 1999.
[Lu2008] W. Lu, W. Sun and H. Lu, “Robust watermarking based on DWT and nonnegative matrix factorization,” Computers and Electrical Engineering, Vol. 35, No. 1, 183-188, 2008.
[Podi2001] C.I. Podilchuk, and E.J. Delp, “Digital watermarking: algorithms and applications,” IEEE Signal Processing Magazine, Vol. 18, No. 4, 33-46, 2001.
[Qi2008] X. Qi, S. Bialkowski, and G. Brimley, “An adaptive QIM-and SVD-based digital image watermarking scheme in the wavelet domain,” IEEE Transactions on Image Processing, Vol. 17, No. 3, 421-424, 2008.
[Tsai2008] M.J. Tsai, C.T. Lin, and J. Liu, “A Wavelet-based Watermarking Scheme Using Double Wavelet Tree Energy Modulation,” IEEE International Conference on Image Processing, 417-420, 2008
[Taub2002] D.S. Taubman and M.W. Marcellin, JPEG2000: Image Compression Fundamentals, Standards and Practice, Kluwer Academic Publishers, Boston, 2002.

[Wang2002] Y. Wang, J.F. Doherty, and R.E. Van Dyck, “A wavelet-based watermarking algorithm for ownership verification of digital images,” IEEE Transactions on Image Processing, Vol. 11, No. 1, 77-88, 2002.
[Wang2004] S.H. Wang, and Y.P. Lin, “Wavelet tree quantization for copyright protection watermarking,” IEEE Transactions on Image Processing, Vol. 13, No 2, 154-165, 2004.
[Web01] http://en.wikipedia.org/wiki/Daubechies_wavelet, last access on May 27, 2010.
[Web02] https://www.digimarc.com/default.asp, last access on May 27, 2010.
[Web03] http://www.alpvision.com/index.html, last access on May 27, 2010.
[Xia1997] X.G. Xia, C.G. Boncelet, and G.R. Arce, “A multiresolution watermark for digital images,” International Conference on Image Processing, Vol. 1, 548-551, 1997.