图像数字水印算法研究

【作者】 张荣；

【导师】 刘传才；

【作者基本信息】 福州大学 ， 计算机应用， 2003， 硕士

【摘要】 随着互联网的发展，人们越来越容易获取数字多媒体信息，而与此同时，数字多媒体信息的版权、保密等问题也变得日益突出起来。因此，多媒体的信息安全保护成了一个研究热点。本文侧重于研究和探讨该研究方向中的数字水印技术。在介绍数字水印的相关概念、特点和应用领域的基础上，对水印信号的数据预处理进行了系统的论述，并指出各种常用方法的优缺点；其次对水印信号的嵌入技术进行了翔实分析，并分析了各类嵌入方法的抗攻击能力；随后提出了两种分别基于DWT和DCT变换的嵌入灰度图水印的新方法，加以实现并对实验结果和算法性能进行初步分析讨论。实例分析表明第一种算法在抗对比度和亮度攻击方面性能优异但是抗压缩性很差，而第二种算法在抗压缩性攻击和缩放重采样攻击方面性能较好。但是本文也发现在抗噪声干扰方面，这两种算法的的性能仍然不够好有待进一步改进；最后展望了数字水印未来可能的研究方向。更多还原

【Abstract】 Following the sharply development of Internet, it is more and more easy to get some digital multi-media information. However, it also causes some problems, such as copyright protection and information encryption, which become more urgency day by day. Therefore, many scholars are attracted by the multi-media information security problem. In this thesis, the author studies one of its branch - digital watermarking of images. First, some basic conceptions, specialties and application domains of it are introduced. Second, the pretreatment of digital watermarking data is discussed one by one, and their shortcomings and excellence are also pointed out. Third, many kinds of embedding technology of digital watermarking data is analyzed carefully, and their powers to resist some kinds of attacks arc introduced. Then, two new embedding technologies about gray digital watermarking are suggested, based on DWT and DCT separately. The author implements them and analyzes their results and performances. The experimental results demonstrate that the second has a better power to resist attack of robust. Finally, the author gives out some suggests on the possible research directions in the future.更多还原