網路的普及使得資訊的傳播更為快速，便利。但卻也造成了侵犯智慧財產權的案例與日俱增。雖然這些在網路上流傳的資料是無形的產物，但其價值卻往往難以估計。當有文字或圖片透過網路傳輸時，我們應該如何確保其歸屬呢？隨著網路的流通這些多媒體資訊很輕易的就會被遭到非法的複製、盜用、散佈。為了探討如何在網路的環境下有效的對多媒體資訊做版權的保護，本篇論文是在小波頻率域下實現，將需要加入版權認證機制的影像圖透過二維小波轉換之後，利用虛擬隨機亂數產生器來選取所要藏入的小波樹，再利用小波樹頻帶間係數的差值來做藏入的動作，最後再利用二維反小波轉換把係數值還原回影像圖。並且透過數位簽章的方式保護浮水印的資訊。數位簽章可以提供認證的機制，避免爭議的發生。而為了增加浮水印的強健性，我們利用BCH code來對藏入的二元序列作編碼的動作。BCH code是一種error correction code，利用代數結構的特性使得藏入影像內的資訊有能力將錯誤修正。最後會使用人眼視覺系統(Human Visual System, HVS)的方法，在人眼可察覺範圍下(JND)，動態找到一個較佳的門檻值，能在提升影像品質與浮水印的強健性中取得平衡。

In recent years, the information bursts out on the Internet. It is more convenient to spread the data through the Internet. But it causes a serious problem. That is copyright violation. Although those images are not really touchable, the values are unpredictable. When we retrieve an image or a text file from the Internet, how can we confirm the copyright of it? These media information are easily copied, reused, and spread. Copyright violation is quite common to be seen on the Internet. The proposed research is to protect the copyright on the Internet. To find a better way for the watermark embedding, we embed the watermark information on the DWT domain. And we use the pseudo-random number generator to generate a key, which is used to select the wavelet tree for embed. We embed the watermark information at the minimum difference of the wavelet tree. And apply the IDWT for the image. In order to improve the watermark correctness, we apply the BCH code which is a kind of error correction code. BCH code uses the character of the algebra which can use the extra redundant information to correct the errors. And finally we use the Human Visual System to find the better threshold between the quality of the watermarked image and the robustness of the watermark logo.

[1] Delp,E.J. and Wolfgang, R. B., “A Watermark for Still Image,” IEEE International Conference on Image Processing, 1996.
[2] Boland, F. M., Ruanaidh, J. J. and Dautzengerg,. C, ”Watermarking Digital Images for Copyright Protection,” Proceedings of the 5^th International Conference on Image Processing and Its Applications, No. 410, 1995.
[3] I. J. Cox, J. Killian, T. Leighton et al., “Secure Spread Spectrum Watermarking for Images, Audio and Video,” in Proc. IEEE ICIP, Lausanne, 1996, pp. 243-246.
[4] I. J. Cox, J. Killian, F. T. Leighton et al., “Secure Spread Spectrum Watermarking for Multimedia,” IEEE Trans. Image Processing, vol. 6, no. 12, pp. 1673-1687, Dec.1997.
[5] H. J. Wang, and C. C. J. Kuo, “Wavelet-based Digital Image Watermarking,” Optics Express, vol. 3, no. 12, pp. 491-496, Dec. 1998
[6] S. H. Wang, and Y. P. Lin, “Wavelet Tree Quantization for Copyright Protection Watermarking,” IEEE Trans. Image Processing, vol.13, no. 2, pp. 154-165, Feb. 2004.
[7] Chuan-Fu Wu, Wen-Shyong Hsieh, “ Image Refining Technique Using Digital Watermarking,” IEEE Trans. On. Consumer Electronics, vol. 46, Issue 1, pp. 1-5, Feb. 2000.
[8] Y. Hu, W. Liu, Y. Deng et al., “Readable Watermarking Algorithm Based on Wavelet Tree Quantization,”in Proc. IEEE ICCCAS, 2004, pp. 579-583.
[9] Chang, C. C., Yeh, Y. C. and Hsiao, J. Y., “A Method for Protecting Digital Image from Being Copied Illegally, ”Proceedings of 2000 Kyoto International Conference on Digital Libraries: Research and Practice, pp.348-355, Japan, Kyoto, Nov. 2000.
[10] J. Huang, and C. Yang, “Image Digital Watermarking Algorithm using Multiresolution Wavelet Transform, ”in Proc. IEEE Int. Conf. Systems, Man and Cybernetics, 2004, pp.2977-2982.
[11] Chang, C.C., Tai, W. L. and Lin, C. C., “A Multipurpose Wavelet-based Image Watermarking,” Proceedings of 2006 International Conference on Innovative Computing, Information and Control (ICICIC2006), vol. 3, Beijing, China, Aug. 2006, pp.70-73
[12] Potdar, V., Song, H.,” Subjective and Objective Watermark Detective Watermark Detection using a Novel Approach Bar-code Watermarking”, Computational Intelligence and Security, International Conference on Volume: 2, Nov.2006, pp.1203 - 1208
[13] Mirza, H.H., Thai, H.D.,” Digital Video Watermarking Based on Principal Component Analysis,” Innovative Computing, Information and Control. ICICIC ' Second International Conference on Digital Object Identifier, Sept. 2007, pp.290-290
[14] H. Inoue,A. Miyazaki, A. Yamamoto, and T. Katsura, “A Digital Watermark Based on the Wavelet Transform and its Robustness on Image Compression and Transformation,”IEICE Trans. Fund. Electron., Commun., Comput. Sci., vol. E82-A, pp.2-10, Jan. 1999.
[15] Akl, S. “Digital Signatures: A Tutorial Survey.”Computer, February 1983.
[16] A. S. Lewis and G. Knowles, “Image Compression Using the 2-D Wavelet Transform,” IEEE Trans. Image Processing, vol. 1, pp.244-250, Apr.1992
[17] S. LIN, D. J. Costello and JR. “Error Control Coding Fundamentals and Applications—2/e”, 2004 by Prentice-Hall, Inc.
[18] W.H. Lin and S.J. Horng and T.W. Kao “Image Copyright Protection with Forward Error Correction”, Expert Systems with Applications 36(2009)
[19] S. L. Hsieh, j. j. Jian “A Color Image Watermarking Scheme Based on Secret Sharing and Wavelet Transform,” IEEE March 16, 2007
[20] USCSIPI---The USC-SIPI Image Database.[online] Available: http://www.sipi.usc.edu/services/database/Database.html.
[21] F. A. P. Petitcolas, Weakness of existing watermark scheme, 1997 [online] Available:http://www.petitcolas.net/Fabien/watermarking/stirmark/index.html.
[22] Ulead system, Inc., PhotoImpact 11 software
[23] B. K. Lien, and W. H. Lin, “A Watermarking Method Based on Maximum Distance Wavelet Tree Quantization,” in Proc. 19th Conf. Computer Vision, Graphics and Image Processing, 2006, pp. 269-276.
[24] E. Li, H. Liang, and X. Niu, “Blind Image Watermarking Scheme Based on Wavelet Tree Quantization Robust to Geometric Attacks,” in Proc. IEEE WCICA, 2006, pp. 10256-10260.
[25] Wei-Hung Lin, Yuh-Rau Wang*, and Shi-Jinn Horng, “A Wavelet-tree-based Watermarking Method Using Distance Vector of Binary Cluster,” Expert Systems with Applications, vol. 36, no. 6, 2009, pp. 9869-9878, (SCI, EI)