数字水印技术在图像认证和版权保护上的应用

【作者】 王津申；

【导师】 戴跃伟； 王执铨；

【作者基本信息】 南京理工大学 ， 控制理论与控制工程， 2004， 硕士

【摘要】 数字图像和视频由于可以方便的编辑、存储、传输和使用，越来越广泛应用于当今社会。但也出现了篡改信息和破坏信息的现象，因此如何在网络环境下实现有效的版权保护和信息安全已成为一个重要的现实问题。 论文中提出一种JPEG图像内容认证的新颖水印算法。图像认证方法是基于一种半脆弱特征，这种半脆弱特征具有区分“内容保持”和“恶意篡改”的能力。因此我们提出的算法可以确定和定位攻击。 还提出一种应用于版权保护的鲁棒水印算法。利用通信理论中的信道估计原则，用提取出的参考水印和已知的参考水印对信道进行估计，并根据贝叶斯(Baves)决策理论，对提取出的水印进行决策，以提高水印的鲁棒性。更多还原

【Abstract】 Digital images and videos are more and more widely used in nowadays society. They are much more convenient in editing, storing, transmitting and usage. But unfortunately, due to the malicious modification, digital media become unsafe. Therefore, effective copyright protection and multimedia security are becoming a highlight.In this thesis, a novel approach to content authentication for JPEG images is proposed. The image authentication method is based on a semi-fragile feature. Our proposed scheme has the capability of differentiating "content preserving" modifications from "malicious" attacks and so can ascertain and locate the "malicious".Also, we proposed a robust watermarking algorithm for copyright protection. We employ channel estimation principles to improve the performance of robust watermarking. A binary symmetric channel (BSC) model of the watermark channel is introduced to more accurately characterize signal tampering. By relying on statistical Bayes decision theory, we make decisions on the extracted watermark to further improve the performance.更多还原