基于Logistic映射的小波域图像加密技术

针对图像小波编码混沌加密技术中出现的边界效应问题,提出基于区间小波编码的混沌加密新技术。相对于传统的图像延拓方法,该方法在小波变换前后,不需要对图像进行特殊的延拓处理,可在对图像加密的同时,压缩图像文件规模,有效消除边界效应;此外,调整被逼近信号函数的H lder连续指数L的大小,可满足对图像恢复精度的不同要求。实验结果表明,在L=1时,信号恢复精度已满足要求。

Image encryption technology based on Logistic mapping in wavelet domain

To eliminate boundary effects in image a new image chaos encryption technology,the chaos encryption based on interval wavelet coding,is proposed.Compared with the traditional image extent method,the special extent processes is no longer necessary in this method before the wavelet transform(WT) to image and after the inverse wavelet transform(IWT) to chaos encryption serials.The test results shows that this method can be used to eliminate the boundary effect and compress the image file.Besides,the value of parameter L can be changed to meet various precision requirements for reconstruction of an image.