摘要
多媒体技术和网络技术的发展，给人们带来了丰富多彩的视听娱乐的数字产品。但是由于数字产品复制不会引起质量下降，因此出现的大量盗版现象严重地损害了生产商和著作者的积极性，数字产品市场迫切需要加强版权保护工作的手段。数字水印技术作为数字产品版权保护的有效手段，成为多媒体安全研究的热点，其中视频数字水印成为近年来新的研究热点，有许多学者针对现有的国际视频标准提出了多种视频水印方案。
本文对图像水印技术和视频水印技术的发展和现状及主要技术方法作了介绍，以及离散小波变换在水印技术中的应用前景和方法。在此基础上针对视频与图像的异同点，分析比较了静态图像水印和视频水印特点的异同，并且结合在Internet上传输视频时，网络自身的特性(比如带宽资源等)对视频流产生的影响，以及这些影响对视频流水印技术的特殊要求，结合基于对象的视频编码标准MPEG-4的特性，提出了在视频对象中利用基于小波变换的水印方案。
该方案考虑了MPEG-4视频编码基于对象的特性，以及伸缩特性对视频水印的特殊要求，结合小波变换的多描述特性，该特性允许水印除了在最底层检测以外可在各个分辨率进行，这样就能够实现在视频质量最低的情况下也能够检测到水印，从而提高了水印在视频流中的鲁棒性。最后分析了基于对象的视频流水印的优点。
With the development of multimedia and Internet technology, there are more and more digital products for our entertainment and it can be easily copied and delivered on Internet without any loss in quality. So more and more pirates strongly hurt the producer and author's interests. An effective method is required to protect the digital products. Digital watermarking is such an effective method and it attracts many researchers, especially digital video watermarking. In recent years there are many digital watermarking techniques for popular video compression standards.
In the paper some images and video watermarking techniques are introduced, including their development and general method to research. It also covered with wavelet for it's role in JPEG2000 and MPEG-4 and it's application in watermarking with its multiresolution property. Comparison and analysis of image and video' watermarking is made based on the difference between images and video. When the digital streaming video is transmitted on Internet, it will be affected by the network, such as bandwidth, so the paper also deals with streaming video watermarking and its exclusive requirement. At the last chapter, an object-based watermarking algorithm has been presented.
The watermarking algorithm for MPEG-4 compression is devoted to address the influence from the rate scalability, based on static texture object in MPEG-4 and watermarking in wavelet domain. The possibilities and advantages that an object-based watermarking combined with watermarking agent techniques are pointed out.
引文
1. Mitchell D. Swanson Bin Zhu Benson Chau, Multiresolution video watermarking using perceptual models and scene segmentation, in proc of IEEE, 1997
2. Cox, J., Killian, J., Leighton, T., et al. Secure spread spectrum watermarking for multimedia. IEEE Transactions on Image Processing, 1997,6(12):1673—1687.
3. Gonzalez, C., Wintz, P. Digital Image Processing. 2nd Edition, Addison-Wesley Publishing Co/IEEE Press, 1987.
4. A. S. Lewis and G. Knowles. Image compression using the 2D wavelet transformation. IEEE Trans. Image Processing, pp 244-250, April 1992
5．郭峰，张春田，应用于版权保护的视频数字水印，数字视频2001年第6期，p21-23
6．赵健，谢红梅，俞卞章，小波理论的应用研究及新思路，数字电视与数字视频，2002年第6期
7．邢培育，崔克清，基于小波理论的图像压缩算法，南京化工大学学报，第23卷第4期2001年7月P77-79
8．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
9．杨易先，钮心忻，任金强，信息安全新技术，北京：北京邮电大学出版社，2002．P47-88
10．刘振华，易萍，信息隐藏技术及其应用，北京：科学出版社，2002，P71-147
11．刘峰，苏育挺，张春田，MPEG-2码流中的数字水印，通信学报，2000年11月21卷第11期．P1-6
12．钟玉琢，王琪，贺玉文，基于对象的多媒体数据压缩编码国际标准—MPEG-4及其校验模型，北京：科学出版社，2000
13．汪一鸣，徐清源，李筑文，序列图像的多码率混合编码及其性能，通信学报2001年11期，P86-92
14. Wenwu Zhu, Zixiang Xiong, Ya-Qin Zhang, multiresolution watermarking
for images and video:a unified approach, IEEE, 1998
15. Wenwu Zhu, Zixiang Xiong, Ya-Qin Zhang, multiresolution watermarking for images and video, Transactions on circuits and system for video technology, vol. 9 NO. 4, June, 1999 IEEE.
16. Frank Hartung, Bernd Girod, digital watermarking of -2 coded video in the bitstream domain, IEEE, 1997, P2621-2664
17．黄达人，刘九芬，黄继武，小波变换域图像水印嵌入和对策算法，软件学报，2002，Vol．13，7
18. MPEG-4 Natural Video Coding-An overview http://leonardo, telecomitalialab, com/icjfiles/-4 si/7-natural vi deo paper/7-natural video paper. htm, 2003, 1
19．林刚，刘泽民，一种新的可扩展小波视频编码方法，高技术通讯，1999，5
20. Xiaoyun Wu, Wenwu Zhu, Zixiang Xiong等, object-based multiresolution watermarking of images and video, IEEE international symposium on circuits and systems, may 28-31, 2000, Geneva, Switzerland.
21．刘红梅，黄继武，肖自美，一种小波变换域的自适应水印，电子学报，2001年12月12期
22. Swanson M, Zhu B, Tewfik A, data hiding for video in video, proc, IEEE, Int. Conf. on image process.
23. Swanson M, Zhu B, Tewfik A, object-based transparent video watermarking, in proc 1997, IEEE multimedia signal processing wk-shp, 369-374
24. Xiaoyuan wu, Wenwu zhu, Zixiang Xiong, etc., object-based multiresolution watermarking of images and video, IEEE, International Symposium On Circuits And System, May, 28-31,2000
25. F. Hartung and B. Girod, watermarking of uncompressed and compressed video, signal processing, vol 66, no. 3, pp288-301, May 1998.
26. G. Langelarr, R. lagendijk, and J. Biemond, watermarking by coefficient removal: a statistical approach to optimal parameter settings, proceedings of the SPIE security and watermarking of multimedia contents, vol, 3657, PP. 2-13, San Jose, California, January, 25-27, 1999
27. Frank Hartung, peter eisert, bernd girod, digital watermarking of MPEG-4 facial animation parameters, compuer&graphics, 1998, 22 (3) 425-435
28．戴元军，基于扩展频谱的视频水印技术的研究与实现，http://www-900.ibm.com/developerWorks/cn/cnpapers,nsf/security-papers
29. Hartung F H, Su J K, Girod Spread B, spectrum watermarking:malilious attacks and counterattacks. Security and Watermarking of Multimedia Contents. proceedings of SPIE Vol 1999, 3657:147-158
30. Eugene T. Lin, Christine I. Podilchuk, ton kalker等, streaming video and rate scalable compression:what are the challenges for watermarking?, www.ecn.perdue.edu
31．刘九芬，黄达人，胡军全，数字水印中的双正交小波基，中山大学学报，2002年7月。
32．崔锦泰，小波分析导论[M]．西安：西安交通大学出版社，1995