基于小波变换及矢量量化的隐像术

提出了一种新的图像保密系统（称为隐像术），它把有关秘密图像的信息加密隐藏在另一可以开传送的普通图像中，不易引起窃听者的注意，达到了保护秘密图像的目的。试验结果表明，恢复出的秘密图像的PSNR值可达22．83dB，证明了隐像术有着令人满意的恢复质量。隐像术的优点是：用可公开传送的普通图像隐藏秘密图像，不易为窃听者所察觉；有效地压缩了所需保密和数据，一幅可公开传送的普通图像中可隐藏数幅秘密图像；秘密图像的信息是用DES算法加密的，确保了整个系统的安全性。

IMAGE HIDING CRYPTOSYSTEM BASED ON WAVELET TRANSFORM AND VECTOR CODING

A novel kind of image cryptosystem—image hiding cryptosystem is proposed in this paper. The key information of secret image is encrypted and then hidden into another image, which can be publicly accessed. Because it is ordinary image, it will not attract the attention of illegal eavesdropper and the secret image is protected well by the camouflage and the encrypt algorithm. The experiment shows that the PSNR of the restored secret image can be as high as 22.83 dB, indicating that the restored secret image has satisfactory quality. The new crypto-system has three benefits. First， the secret image is protected by the camouflage which is an ordinary image publicly accessed. Second, the cryptosystem compresses image data using wavelet transform and vector coding. Third, information of secret image is encrypted by the DES algorithm, which ensures the system's security.