【作者】 李海燕；

【导师】 张佑生；

【作者基本信息】 合肥工业大学 ， 计算机应用技术， 2008， 硕士

【摘要】 随着网络技术和多媒体技术的飞速发展,如何保护数字产品的安全和版权的问题,已经成为世界各国极为关注的重要课题。数字水印技术就是在这个背景下应运而生的,它可以有效地弥补传统信息加密方法的缺点,在认证、防伪、防篡改,保障数据安全和完整性等方面具有广泛的应用前景。目前的数字水印技术发展得十分迅速,并且已经取得了丰硕的成果。本论文对静态图像的数字水印技术的理论和方法进行重点研究,所作的主要工作如下:1.介绍了信息隐藏和数字水印的概念,并从水印的生成、嵌入、提取、检测和攻击五个方面阐述水印系统的基本框架,对数字水印技术的分类、特点、典型算法和应用领域进行了简单的介绍。2.根据人类视觉系统的特点,提出了基于DWT和DCT域的水印嵌入算法,并用实验验证了算法的有效性。3.根据人类视觉对彩色图像的感知特性,设计出一种新的水印算法。该算法选取二值图像作为水印,对其进行置乱加密后嵌入作为载体的彩色图像绿色分量的DCT中频系数中。实验表明,用该算法嵌入水印的图像质量没有明显下降,并且嵌入的水印信息具有良好的鲁棒性。更多还原

【Abstract】 Along with the fast development of internet and multimedia, the problem about how to protect the information of multimedia and digital products has already been an important issue cared by all the countries in the world. Digital watermarking occurred in such a background, which can make up the shortcomings of traditional methods of information cryptology, and has widely used in the fields of authentication, prevent-counterfeiting, prevent-tampering, safety and security of data. Nowadays the digital watermarking is developing quite quickly, and a lot of achievements have been obtained.The paper focuses on the theory and methods of digital watermark in static image. The main work having been done are as follows:The basic conception of information hiding and digital watermark and the framework of digital watermark system are discussed, which include watermark production, embedding, detection, extraction and attacks being encountered. The classification and features of digital watermark technology, representative algorithms and applications are introduced.According to the characteristics of human visual system, an algorithm of embedding watermark is discussed in detail, which is based on both DWT and DCT. And some experiment results are given, which validated that the algorithm is effective.According to the apperceive features of human vision, an algorithm of watermark is proposed, which uses the green weight of a color image. The experiment results show that the algorithm can well keep the original image quality and has better robust.更多还原