近年來有許多學者提出多目的數位浮水印(Multipurpose Digital Watermark)之技術，嵌入多目的數位浮水印之目的是利用不同浮水印之特性以達成多種的用途，較常見的是將強健型及易碎型浮水印依序嵌入，希望結合二者的優點以達到多功能浮水印的效果。而在JPEG壓縮格式中嵌入此類型之數位浮水印，對網路媒體傳輸可達保護與認證之目的。
本論文在JPEG影像上提出一個具有易碎與強健特性的數位浮水印技術，此技術利用多組重覆之易碎型浮水印再計算出區塊特徵與相關值嵌入於JPEG之離散餘弦轉換域量化後係數中。此浮水印可保護所有量化後係數，達到易碎型浮水印影像完整性認證(Integrity Authentication)的效果。所嵌入之易碎型數位浮水印，利用重覆碼(Repetition Code)之機制具有可還原成著作權資訊的特性，因此亦具有強健型浮水印著作權保護的效果。此外在區塊相關值計算時利用一嵌入因子(Embedding Factor, EF)計算出影像區塊特徵相關性(Block Feature Correlation)，即可在浮水印的易碎性與強健性之間作調整，達到兼具著作權保護與竄改定位上之目的。
本論文所提出之浮水印技術經由實驗證明，在影像受到局部竄改或攻擊時能夠以影像區塊為單位偵測出受到竄改或攻擊之部份，藉由影像區塊特徵相關性的嵌入方式可抵抗剪下-貼上攻擊(Cut-and-Paste Attack)、向量量化攻擊(Vector Quantization Attack)與移植攻擊(Transplantation Attack)等目前已被提出的攻擊方法亦可偵測出被攻擊之區塊。在著作權保護方面經由，實驗結果可知即使整個影像皆加入高斯雜訊或經過低通濾波器，亦可由浮水印還原所嵌入之著作權資訊證明影像著作權之歸屬，達到著作權保護之功能。

Multipurpose digital watermarking techniques are published in recent years. Those techniques embed the different watermarks such as fragile and robust for combining the advantages. In this paper, we propose a multipurpose watermarking technique with fragility and robustness on JPEG image. First, we generate many watermarks with the user key and copyright information so that they are different from each others. Then calculate the image block features and the correlations for embedding those watermarks into the Discrete Cosine Transform (DCT) coefficients. By using the Repetition Code mechanism, those embedded watermarks can be converting to original copyright information that is used to generate those watermarks so that it obtains the function of copyright information protection. Because of the Embedding Factor (EF) is used to calculate the image block correlations, the watermarking technique can adjust between the fragility and the robustness of the embedded watermarks. By the experiment result, this technique can detect the modified regions with block unit and overcomes the cut-and-paste attack, vector quantization attack and transplantation attack. The copyright information has a strong robustness to low pass filter and Gaussian noise.

[1] Bijan G. Mobasseri, Senior Member, IEEE, and Robert J. Berger, II, "A Foundation for Watermarking in Compressed Domain", IEEE Signal Processing Letters, Vol. 12, No. 5, Page(s):399 - 402, MAY 2005

[2] C.-T. Li, "Digital fragile watermarking scheme for authentication of JPEG images", IEE Proc.-Vis. Image Signal Process, Vol. 151, No. 6 ,Page(s):460 - 466, December 2004

[3] Chun-Shien Lu, Member, IEEE, and Hong-Yuan Mark Liao, Member, IEEE, “Multipurpose Watermarking for Image Authentication and Protection”, IEEE Transactions on Image Processing, Vol. 10, No. 10, Page(s):1579 - 1592, OCTOBER 2001

[4] David W. Cook II and P. K. Rajan, Fellow, IEEE, "TIAMAT: A New Fragile Watermarking Technique for Image Authentication", IEEE System Theory Proceeding of the Thrity-Eighth Southeastern Symposium on 5-7, Page(s):221–225, March 2006

[5] Gregory K. Wallace, "The JPEG Still Picture Compression Standard", Consumer Electronics, IEEE Transactions, Vol. 38, Issue 1, Pages xviii-xxxiv, 1992

[6] Haifeng Zhu , Chunhui Zhao, Chunming Tang, "A Fragile Watermarking Scheme For Tamper Detection and Recovery of Image", Proceedings of the 6th World Congress on Intelligent Control and Automation, Page(s):9748 - 9751, June, 2006

[7] http://www.ijg.org/

[8] Matthew Holliman and Nasir Memon, “Counterfeiting Attacks on Oblivious Block-wise Independent Invisible Watermarking Schemes”, IEEE Transactions on Image Processing, Vol. 9, No. 3, Page(s):432 - 441, March 2000

[9] Mehmet Utku Celik, Student Member, IEEE, Gaurav Sharma, Senior Member, IEEE, Eli Saber, Senior Member, IEEE, and Ahmet Murat Tekalp, Senior Member, IEEE, "Hierarchical Watermarking for Secure Image Authentication With Localization", IEEE Transactions on Image Processing, VOL. 11, NO. 6, Page(s):585 - 595 , JUNE 2002

[10] Paulo S. L. M. Barreto, Hae Yong Kim, Vincent Rijmen, "TOWARD A SECURE PUBLIC-KEY BLOCKWISE FRAGILE AUTHENTICATION WATERMARKING", IEE Proc. Vis. Image Signal Process., 148, (2), pp. 57–62, 2002

[11] Ping Wah Wong, Senior Member, IEEE, and Nasir Memon, Member, IEEE, "Secret and Public Key Image Watermarking Schemes for Image Authentication and Ownership Verification", IEEE Transactions on Image Processing, Vol. 10, NO. 10, Page(s):1593 – 1601, OCTOBER 2001

[12] YUAN Jun, CUI Guo-hua, ZHANG Yi-jia, "A Practical Multipurpose Color Image Watermarking Algorithm for Copyright Protection and Image Authentication", IEEE Digital Telecommunications, ICDT'06 International Conference, Page(s):72 – 72, 2006.

[13] Zhe-Ming Lu, Member, IEEE, Dian-Guo Xu, Member, IEEE, and Sheng-He Sun, "Multipurpose Image Watermarking Algorithm Based on Multistage Vector Quantization", IEEE Transactions on Image Processing, Vol. 14, No. 6, Page(s):822 – 831, JUNE 2005

[14] 陳同孝,張真誠,黃國峰,“數位影像處理技術”,pp.1-9, 旗標出版社,92年出版。