【作者】 刘红军；

【导师】 徐汀荣；

【作者基本信息】 苏州大学 ， 计算机应用技术， 2008， 硕士

【摘要】 网络技术和多媒体技术的迅猛发展,为多媒体信息的存储、获取和分发提供了极为便利的条件,但随之而来的作品侵权、篡改及网络信息的非法截取和查看等问题也日益严重。版权保护和保密通信两大应用需求,成为信息隐藏技术的主要推动力。在信息安全领域,信息隐藏也是研究的热点方向。传统的加密技术保护了信息内容,但却暴露了通信过程,而信息隐藏技术能在保护信息内容的同时,隐藏通信过程,从而提供更高的安全性。隐写术是信息隐藏技术的一个重要分支,主要应用于隐蔽通信。本文针对基于图像变换域的隐写术进行了深入研究,主要工作如下:1.通过对离散小波变换、离散余弦变换和彩色图像的色彩模型及色彩模型间转换的研究分析,提出了基于彩色图像的混合变换域隐藏算法。算法首先从彩色图像的某种色彩模型下提取出载体图像,对载体图像先后进行离散小波变换和离散余弦变换,将秘密信息以量化方式嵌入混合变换域系数中。实验结果表明,混合变换域算法对抵抗常见图像攻击具有较好的鲁棒性。同时,基于不同的色彩模型,混合变换域算法性能会有所差异。2.研究了小波包变换的相关理论,提出了基于小波包变换的多区域信息隐藏算法。小波包变换是小波变换的扩展和延伸,小波包能够提供更加精细的分析方法,对小波分解中没有分解的高频部分作进一步细分,从而拓宽了嵌入空间,并且小波包变换存在最优小波包基。算法首先对载体图像进行最优小波包变换,然后选取若干频域子带作为嵌入区域,将秘密信息重复地嵌入到这些区域,信息提取时采用了二次提取的方式。实验结果表明,算法具有较好的不可感知性,对常见图像攻击具有较好的鲁棒性。3.以本文的算法为基础,设计并实现了一个基于图像的信息隐藏原型系统。更多还原

【Abstract】 With the development of network technology and multimedia technology, multimedia information can be conveniently storaged, accessed and distributed. But the following problems are also increasingly serious, such as the illegal interception and view of network information and so on. The intense demands of copyright protection and secure communication have accelerated the development of information hiding technology. In the field of information security, information hiding is a hot research direction too. Traditional encryption technology can protect the information content, but it exposed the communication process. Compared with the encryption technology, information hiding technology can hide the communication process, thereby providing a higher level of security. Steganography is an important branch of information hiding, mainly used in the covert communications. This paper researches the steganography based on image transform domain, the principal tasks are as follows:1. An algorithm is proposed based on hybrid transform domain of color image, which is based on research and analysis about DWT, DCT and color models of color image, and the transformation between the color models. The algorithm first extracts a component from a kind of color model of color image as carrier image, then making discrete wavelet transform of the carrier image, and doing discrete cosine transform of the result from the DWT. Lastly, embedding the secret information into the coefficients of hybrid transform domain by using quantization embedding idea. The experimental results show that the proposed algorithm based on hybrid transform domain has strong capability in resisting common image attacks. At the mean time, comparing with the different color models, the performance of the algorithm will vary.2. Through research the theory of wavelet package transform, an algorithm based on wavelet package transform on multi-section is proposed. The wavelet package transform is the expansion and extension of the wavelet transform, it can provide more sophisticated analysis method and decompose the high frequency that not decompose in wavelet transform, thereby widening the embedded space. The algorithm first making best wavelet package transform of the carrier image, and then choose some sub-band frequency as embedded sections, then embedding the secret information into the extracted sections using repeat manners. Information extracting taking the method of double extracting. The experimental results show that the algorithm has good performance on imperceptible. At the same time, the algorithm has good robustness in resisting common image attacks.3. According the algorithms introduced in this paper, we design and implement an information hiding prototypical system based on digital image.更多还原