【作者】 董绍锋；

【导师】 郭宝龙；

【作者基本信息】 西安电子科技大学 ， 模式识别与智能系统， 2006， 硕士

【摘要】 多媒体技术和计算机技术的发展，使得人们创作、使用多媒体数字产品变得越来越容易，互联网技术的发展极大的推动了多媒体信息的广泛传播。然而，由于数字产品复制不会引起质量下降，非法用户可以容易的获取、复制、传播数字多媒体产品，这极大的损害了版权所有者的经济利益。多媒体信息安全成为一个非常重要的现实问题。数字水印技术(Digital Watermarking)，在不影响原始数据正常使用的情况下嵌入版权信息，并且该信息不易被除去，只能由专用的水印提取算法才能检测其中的信息。因此，数字水印技术作为数字产品版权保护的有效手段，成为多媒体信息安全研究的重点，其中视频数字水印更是当前研究的热点。本文对视频水印技术的发展和现状以及主要技术方法作了介绍，分析了数据加密和数字水印技术在版权保护中的优缺点：加密技术只能保证数据资料在加密状态下的安全性，若数据资料一旦被解密，可以任意复制、篡改；水印技术无法阻止多媒体信息复制与传播，但可证明数字作品的版权，追踪非法侵权源头；结合MPEG-4多媒体数据压缩标准，针对MPEG-4视频提出了一种基于图像加密和数字水印的版权保护方案—CPEW(Copyright Protection based on Encryption and Watermarking)。该方案充分考虑了数据加密和数字水印技术在版权保护中的优缺点，MPEG-4视频编码系统结构特性，DCT变换被MPEG广泛采用的优点，将加密技术的多媒体信息传输安全和数字水印技术的版权侵权追踪两者优势结合，在频域对视频图像进行有选择的加密，保证了视频数据网络传输安全性；利用扩频数字水印在帧内编码图像中嵌入版权信息，确保了视频数据的版权。实验结果表明，该方案的加密算法有效保护了视频的传输安全性；数字水印算法对于MPEG压缩、加噪以及滤波操作具有一定的鲁棒性。该方案在网络视频传输中具有广泛的应用价值。更多还原

【Abstract】 With the development of multimedia and computer technology,people create and use digital media product more easily,and the development of Internet promotes the wide-spread of multimedia information.However,because the digital products can be copied without any degradation in quality,illegal users can easily access,duplicate and spread them,which heavily damaged the copyright owner’s economic interest.So security of multimedia information becomes an important issue.Digital Watermarking technology can embed copyright information into original data without any effects on use of the data,and the watermark can’t be removed,only special extracting algorithm can extract it. So digital watermarking as an effective method of copyright protection becomes an exciting research field,especially hot the video digital watermarking.In this paper,video watermarking techniques are introduced,including their development and general method.The relative merits of data encryption and digital watermarking in copyright protection is analyzed:encryption only secure the data in encrypted state,once deciphered,the data can be copied and tampered randomly;digital watermarking can not stop the duplicating and transmitting,but it can trace the illegal users;Combined the MPEG-4 multimedia data compression standard,this paper proposes an approach for protecting the copyright of MPEG-4 video-CPEW(Copyright Protection based on Encryption and Watermarking),which bases on the encryption algorithm and digital watermarking.Considering the relative merits of data encryption and digital watermarking in copyright protection,the characteristic of MPEG-4 CODEC,the merits of DCT Transform,combined with the merits of encryption and watermarking,this approach only encrypts some parts of the picture data in frequency domain to ensure the security of video transmission,and embeds the copyright information using Spread Spectrum watermarking in intra-coded frames to protect the copyright of MPEG video.Experimental results indicated the encryption algorithm of CPEW secured the video effectively;the watermarking algorithm of CPEW is robust for MPEG compression,noising,filtering.This approach has abroad application value in network video transmission.更多还原