基于非下采样Contourlet变换和Hill编码的图像隐写  

Image steganography based on nonsubsampled Contourlet transform and Hill cipher

作　　者：孙树亮[1,2] 

机构地区：[1]福建师范大学福清分校电子与信息工程学院,福建福清350300 [2]福建师范大学福清分校创新信息产业研究所,福建福清350300

出　　处：《电信科学》2016年第6期124-128,共5页Telecommunications Science

基　　金：国家自然科学基金资助项目(No.61473329);福建省科技厅基金资助项目(No.2016J05153)~~

摘　　要：在非下采样Contourlet变换（NSCT）和Hill编码的基础上,提出了一种新的隐写方法。首先把载体图像用NSCT进行分解,得到一幅低频和若干幅高频图像。NSCT提供了图像多方向和多尺度的表示。选择一幅高频图像作为载体来嵌入秘密数据。在嵌入之前,用Hill密码对秘密数据进行编码。Hill密码最重要的是如何找到合适的编码矩阵。编码矩阵应满足的条件是可逆,同时要与字母的个数互质。为了改善隐写图像的视觉效果,采用了2^k修正法进一步减小隐写图像和载体图像之间的视觉误差。实验证明,提出的方法具有更好的图像质量,因此更具有优越性。A novel image steganography was proposed, which was based on nonsubsampled Contourlet transform（NSCT） and Hill cipher. Firstly, cover image was decomposed with NSCT. It provided a multi-scale andmulti-directional representation of an image. One of subbands was selected to embed secret data. Then Hill cipherwas applied to encrypt the secret message. How to find a proper cipher matrix was important in this way. Theselected matrix should be inevitable and relatively prime to the number of alphabets. The skill of 2k correction wasapplied to ease the difference between cover and stego image. Experiment results show that both stego image andretrieved image have better image quality with the proposed approach than other methods.

关 键 词：NSCT Hill编码 2k修正 编码矩阵 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]