摘要
提出一种图像压缩和加密相结合处理方法。利用小波变换的多分辨率特性,对灰度图像进行小波分解,得到低频近似分量和三个方向的细节分量;根据人眼视觉特性,对细节部分系数矩阵进行阈值调制,实现对图像的压缩;利用混沌系统伪随机、遍历性等特性,对集中了原图大部分能量的低频近似系数矩阵进行混沌置乱,实现对图像的加密;用阈值调制后的细节系数矩阵和置乱后的低频加密矩阵进行小波反变换,得到最终的图像。仿真结果表明,此算法在压缩和加密的结合处理上,表现出良好的性能。
An algorithm was proposed in view of the combination of image compression and encryption. We got the approximate part and three detail parts after transforming the image with discrete wavelet transform （DWT）, and compressed the image by modifying the detail parts by a given threshold value based on human visual systems. And then, we encrypted the image by scrambling the approximate part because this part held mostly of the energy. Last, a compressed and encrypted image can be achieved after DWT. Simulation result shows a good effect on the combination of compression and encryption.
出处
《重庆大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2008年第8期918-921,共4页
Journal of Chongqing University
基金
重庆市自然科学基金资助项目(2006BB2227)
关键词
小波变换
图像压缩
混沌置乱
加密
wavelet transform
image compression
chaotic scrambling
encryption
