抗印刷和扫描的数字水印技术研究

【作者】 杜鹏超；

【导师】 车培轩；

【作者基本信息】 电子科技大学 ， 控制理论与控制工程， 2003， 硕士

【摘要】 近年来随着计算机技术的飞跃发展，数字媒体存储与传输技术的进步，数字媒体的版权保护正受到日益严重的挑战，信息安全系统正变的不堪一击，传统的信息加密技术在开放的网络面前，极易被破解。同时由于技术的进步，导致各种伪劣产品、假证件随处可见。在这种情况下，一种新的版权保护、信息隐藏、商品、证件防伪技术——数字水印技术蓬勃发展起来。数字水印技术是永久镶嵌在数字媒体中具有可鉴别性的数字信号，并且不影响数字媒体的可用性。该技术是往数字媒体中添加一定量的信息，在对原始数据作微小修改之下使之具有版权保护或者信息隐藏、防伪的功能。版权保护和防伪技术一直是人们关心的热点，以往的数字水印技术主要围绕数字媒体的版权保护而进行算法设计，很少针对商品、证件的防伪应用。这主要是由于印刷和扫描过程对数字水印的攻击性太强，多数水印算法在经过D/A、A/D转换后就无法检测或者提取数字水印了。本文特别针对印刷和扫描给数字图像带来的误差的问题，设计了一种新的水印算法，综合运用了伪随机处理技术、动态自适应技术、不同应用选择不用频带处理技术、随机位置嵌入技术、多通道嵌入等技术，使得本文所设计的水印算法能够抵抗印刷和扫描的物理转换过程，同时本文所设计的水印是二值图像，能够承载大量的信息，例如个人ID、机密信息、商标标识，甚至可以是一幅地图。因此本水印算法不但能够应用于数字媒体的版权保护，还能应用于保密通信、信息隐藏，更能应用于商品、证件的防伪之中。实验结果表明，本文的水印算法具有抗裁剪性能强、抗缩放性能强、抗JPEG压缩性能好、抗噪声作用好、误检率低、抗打印特性好的特点，完全能够抵抗印刷和扫描攻击，较好地满足防伪的要求，同其他防伪技术相比较，大大减少了防伪成本，扩大了数字水印的应用领域，具有很好的社会效益和经济效益。更多还原

【Abstract】 With the development of computer technology and the advancement of digital media storage and transmission, it is a serious challenge that protecting the copyright of digital media. And at the same time, it is easy to break through information security system. The tradition information encryption technology is easy to be cracked under the open network environment. And forgery commodities and certificates can be seen everywhere. So Digital Watermarking(DW) develops quickly. It’s a new technology of copyright protection, information hiding, forgery prevention and detection.Digital Watermarking is a digital signal which is embed into digital media , can be detected or extracted and does not affect the normal use of the digital media. The technology makes digital media has the function of copyright protection and information hiding and anti-counterfeiting printing by embedding a little information into it.Copyright protection and forgery prevention and detection are of great social importance. In the past , the algorithms of Digital Watermarking are designed mainly for the copyright protection of digital media, not for forgery prevention. The main reason is that printing and scanning maybe affect the Digital Watermarking and make it can not be detected or extracted correctly. Aiming at the problem of printing and scanning , the paper designs a new Digital Watermarking algorithm . It takes use of pseudo-random technology, dynamic adaptive technology, multi-channel technology, random position embed technology and so no. So the Digital Watermarking can resist the physical process of printing and scanning. At the same time, the watermark is binary image which includes a great deal of information, such as personal ID, secret information, even a piece of map . So the technology can apply to not only copyright protection ,but also information hiding and forgery prevention.The experiment results show that the proposed algorithm can resist cropping operation, scaling operation and JPEG compression, printing and scanning. Comparing with other forgery prevention and detection technology, the performance of forgery prevention is proved better. The algorithm described in the paper reduced the cost of forgery prevention , and enlarges the application fields. It will bring great social benefits and economic benefits.更多还原