【作者】 王文君；

【导师】 付炜；

【作者基本信息】 燕山大学 ， 电路与系统， 2004， 硕士

【摘要】 摘 要 随着计算机网络技术和数字多媒体的迅速发展，图像、视频等数字化的产品非常普遍，带给了人们丰富、及时、便利的大量信息，但同时引发出数字信息安全问题和数字产权的安全问题。如何在网络环境中实施有效的版权保护和信息安全手段，已经引起学术界、企业界以及政府部门的广泛关注。 传 统 的 信 息 安 全 加 密 方 法 有 很 大 的 局 限 性 ， 数 字 水 印 (DigitalWatermarking)技术的提出为解决数字化信息的版权问题提供了新的有效的方法，半脆弱性数字水印技术不仅保护媒体中的水印不被篡改或去掉，同时还能抵抗一些正常的处理(如压缩)，有的水印方法还能确定出被篡改的位置或性质。 本文的研究分为四个部分：第一，提取水印：针对不同分辨率的遥感影像采用二进小波提取边缘特征作为零水印；第二，水印置乱：对水印图像采用一种改进的新置乱算法，该算法由仿射变换推导得来，具有很强的信息隐藏性，并且算法简单；第三，水印嵌入：对不同分辨率的多光谱遥感影像采用正交小波包对 R、G、B 三个波段进行分解，然后根据不同的图像在 R、G、B 三个波段的敏感程度，在不同的小分解系数中嵌入不同强度的水印，在水印嵌入过程中产生两个个私有密钥，以备后面检测时使用；第四，半脆弱性水印的检测验证。验证内容包括：根据上述得到的密钥先验证图像是否存在水印，若存在水印，则进一步提取出水印，并根据压缩、加噪和剪切、涂改等方法来验证本文算法的鲁棒性，并确定遥感图像中被篡改的位置。更多还原

【Abstract】 With the development of computer network technology and digitalmultimedia, which supply information for us timely, at the same time thequestion on security of digital information and authenticity are broughtforward. How to bring into effect measure of protect authenticity and securityinformation has paid great attention by academe, enterprise, government.Theconventional means of information security have their characteristic oflocalization, Semi-fragile digital watermarking technology supply neweffective means for protect authenticity and information security, digitalwatermarking not only ensure the watermark is not tampered or get rid of ,butalso resist some normal processing, for example: compression, somewatermarking means has the capacity of located the tamper. The method four departments: Firstly, generate watermarking, extractingedge characters from different resolution RS images with dyadic wavelet asthe zero watermarking; secondly, scramble watermarking, scrambling theimage based on a new method which was deduced from affine transformationand not only had better information cryptic character, but also was easilycomputed; thirdly, embed watermarking, the R,G,B bands of differentresolution multi-spectral image was decomposed by orthogonal waveletpacket，then embedded different intensity of watermarking in sub-bandswavelet packet coefficients separately, and during the course of embeddingwatermarking two private keys were generated; at last, inspect semi-fragilewatermarking, which includes inspecting whether the image included thewatermarking by using the keys attained form the course of embeddingwatermarking, and if it was a marked image, then extracted watermarking, atlast validated the degree of robustness by compressing, cutting, altering andadding noises to it, and located the tamper parts of the image.更多还原