基于dct的数字水印算法.doc

摘要
数字水印技术近年来得到了较大的发展,基于变换域的水印技术是目前研究的热点。数字水印是利用数字作品中普遍存在的冗余数据和随机性,把标识版权的水印信息嵌入到数字作品中,从而可以起到保护数字作品的版权或其完整性的一种技术。
一个有效的数字水印系统至少具备以下三个最基本的特性::数据信息隐藏于数据图像中,不是文件头中,文件格式的变换不应导致水印信息的丢失。:在数字图像作品中嵌入数字水印不会引起图像明显的降质,即含水印的图像与原始图像对人的感觉器官的刺激应该是无差别或差别很小,主观感觉变化很小。:是指在经历有意或无意的信号处理过程后,水印信息仍能保持完整性或仍能被准确鉴别。另外还有通用性、惟一性等特性。数字水印的基本应用领域是版权保护、隐藏标识、认证和安全不可见通信等。
本文提出了一种基于dct域的Matlab水印算法,实验结果表明这种算法具有较好的性能,实现的水印具有不可见性,而且具有较好的鲁棒性。
关键词:数字水印;DCT变换;Matlab程序
Abstract

Digital watermark technology in recent years have seen great development, based on changing domain watermark technology is being studied. Digital watermark is the use of digital works prevailing in the redundant data and random nature of the logo copyright watermark information embedded in the digital works, so as to protect digital copyright or the integrity of a technology.
An effective Digital watermark system at least the following three basic characteristics: 1. Security of data and information hidden in the digital image, not document and the format of the change should not lead to watermark information is missing. 2. hidden in the digital image works that are embedded in Digital watermark there is no image clear of quality, shallow the image of Original image of the People' s receptor of incentives should be no difference or very different, subjective feeling very little has changed. 3. robust, is an experienced intentionally or unintentionally signal processing, watermarks information has been able to maintain integrity or continue to be accurate identification. In addition, only a general nature and characteristics. Digital watermark and applied basic areas of copyright protection, hidden identification, authentication and security cannot munications.
This article presents a based on dct domain Matlab watermark algorithm results table this methodology with a better performance in achieving the watermark is see, and a fairly good robust.
Key words: Digital watermarking; DCT transform; Matlab program