《基于整数小波变换的可逆信息隐藏》由会员分享，可在线阅读，更多相关《基于整数小波变换的可逆信息隐藏（79页珍藏版）》请在金锄头文库上搜索。
1、中南民族大学 硕士学位论文 基于整数小波变换的可逆信息隐藏 姓名：韦一 申请学位级别：硕士 专业：计算机应用技术 指导教师：熊志勇 2011-04-15 中南民族大学硕士学位论文 I 摘 要 随着互联网技术的飞速发展，在网络上制作、拷贝、传播和发布多媒体数字 作品变得更加的容易，信息隐藏技术为日益严峻的多媒体信息安全和知识产权保 护提供了一个十分有效且非常可靠的解决方案，该技术得到了不断的改进，并更 加趋于完善。 与此同时，对于大部分信息隐藏算法而言，在原始载体图像中嵌入了隐秘信 息后，其原始载体的数据不能被无损的恢复，这对原始数据要求极高的应用领域 是不可接受的，如医学和军事领域，而可逆信息
2、隐藏技术的提出恰好可以弥补这 一不足。可逆信息隐藏技术其实质是一种脆弱性水印方案，即在多媒体作品中嵌 入隐秘信息，它的可用性并没有被改变，当其数据受到质疑时，可以把隐秘信息 从多媒体作品中提取出来以鉴别真伪，并且能够无损恢复原始的载体图像。 本文首先介绍了信息隐藏技术的产生背景、相关概念、分类、一般模型、典 型算法、性能评价、研究方向、研究现状和当前存在的问题；然后介绍了连续小 波、离散小波、整数小波等小波变换的基本理论；最后重点围绕如何提高嵌入容 量和改善视觉质量两个方面展开研究。 本文的主要贡献： (1) 提出了一种基于预测扩展和二次可变换性的可逆信息隐藏算法。该算法选择 菱形预测器预测像
3、素值，从而可以确保预测的准确率最高，并把预测误差分成两 类：可变换和不可变换；然后依据预测误差的可变换性生成一个不可变换差值分 布表，即长度为 256 的一维数组，用于记录每一预测值是否存在不可变换差值。 在提取端只需还原不可变换差值分布表，当其元素等于 0 时 ，则对应的预测误差 一定是可以变换的，提取其数据或者恢复其预测误差值。当其元素不等于 0，则变 换性不能确定，因为其中可能包含了可变换的预测误差。为了避免嵌入容量的损 失，进一步引入了预测像素的二次可变换性的方法，用于定位可以变换的预测误 差。由于引入不可变换差值分布表和预测误差二次可变换性的方法都不需要嵌入 溢出定位图，因而嵌入容量
4、得到了极大的提高。实验结果表明，本算法具有良好 的视觉质量和较高的嵌入容量。 (2) 在该算法的基础上，以 Visual Studio 2008 为开发环境，设计了一个灰度图像 可逆信息隐藏系统。实验结果表明：该系统具有嵌入信息、检测信息、提取信息、 认证信息、去除信息、鲁棒性检测、性能检测等功能。 关键词： 可逆信息隐藏；整数小波变换；预测扩展；预测误差扩展；溢出定位图 基于整数小波变换的可逆信息隐藏 II ABSTRACT With the rapid development of internet technology, it has become easier to make, cop
5、y, transmit and distribute multi-media digital works through internet. Among those technologies, Information Hiding Technology provides a very effective and reliable solution to the problem of multimedia information security and intellectual property protection. As this technology is under constant
6、improvement, it turns to be more perfect. Concerning the other studies of information hiding algorithm, the original vector data cannot be recovered without any damage after the original vector image is embedded in the hidden information. This weakness is not allowed to appear in the fields of medic
7、ine and military, for those fields require high quality of original data. Reversible Information Hiding Technology comes into being for meeting the need of such requirement. In essence, this technology refers to a fragile watermarking scheme. Through this technology, the embedment of secret informat
8、ion in the multimedia works doesnt bring any damage to the original image. When the data of the image is doubted, secret information can be extracted from the multimedia work to identify the authenticity of this image. Besides, this technology is able to recover the original image without any damage
9、. This thesis begins with an introduction to some background information of this technology, meaning of study, relevant concepts, classification, general model, the typical algorithms, performance evaluation, evaluation criteria, future research, research status and current problems. Further introdu
10、ction goes to the basic theories of wavelet transform including the continuous wavelet, discrete wavelet, integer wavelet. Finally, much emphasis is put on how to improve the embedding capacity and the visual quality. The main contribution of this thesis lies in: (1) It has proposed a reversible inf
11、ormation hiding algorithm which is based on predicting secondary expansion and adjustment of pixel value. The selection of prediction predictor diamond pixels ensures the highest accuracy of prediction. And the prediction error is subdivided into two categories: transformation and non-transformation
12、. The generation of non-transformational distribution table relies on the transformability of the prediction error. Being the distribution table, the length of 中南民族大学硕士学位论文 III one-dimensional array is 256, which is used to record the corresponding non-transformable different amount of each predicti
13、ve error value. When the amount equals to 0, the predictable error value is transformable. In addition, data can be extracted or predictable error value can be recovered. When the value is not equal to 0, the possibility of transformation is uncertain, for it may contain a convertible predictable er
14、ror. In order to avoid the loss of embedding capacity, the second pixel value adjustment method is further introduced. This method is applied to figure out the predictable error. Since the introduction of the non-transformable error distribution table and the adjustment methods of the pixel values d
15、o not involve the embedment of binary location map, the embedding capacity is accordingly enlarged. It can be concluded from the experiment that the algorithm ensures good visual quality and higher embedding capacity. (2) By employing algorithm, a Reversible information hiding system is created on t
16、he basis of Visual Studio 2008. This system is only operated under the original carrier and the secret information in gray image. The result shows that such kind of system can be applied to embed, inspect, draw, authorize, remove secert information as well as make robustness testing and performance testing. Key Words: Reversible information hiding；Integer wavelet transform；Prediction expansion；Prediction errors expansion； ；O
