二维分段线性混沌映射耦合中国剩余定理的图像加密压缩同步算法

IMAGE ENCRYPTION AND COMPRESSION ALGORITHM BASED ON 2D PHASED LINEAR CHAOTIC MAP COUPLING CHINESE REMAINDER THEOREM

由于当前的图像压缩加密算法都是将扩散和压缩分成两个独立的阶段,无法将二者在一个阶段同步进行,使其产生的压缩比不稳定,导致了压缩质量不佳且难以实现实时性,计算复杂度较高。对此,设计了置乱灰度值序列生成机制;构造了扩散—压缩同步结构;并引入中国剩余定理,将其与混沌映射相融合,提出由二维分段线性混沌映射融合中国剩余定理的图像加密压缩算法。根据2D分段线性混沌映射置乱初始图像,然后利用中国剩余定理产生的压缩比对置乱图像同时进行扩散和压缩。最后在Matlab仿真平台上测试该算法,结果显示:该算法具有优异的加密和压缩性能,生产的压缩比很稳定;且扩散机制高度安全,密钥空间足够大,抗攻击能力大幅度提升。

Since current image compression and encryption algorithms all divide the diffusion and compression into two separate phases, and not able to make them two be executed synchronously in a single stage, this causes the unstable compression ratio and induces poor com- pression quality, moreover it is hard to achieve real-time performance, the computational complexity is quite high as well. To deal with this, we design the generation mechanism of permuted gray level sequence, and construct the synchronised diffusion-compression structure; by in- troducing Chinese remainder theorem and integrating it with chaotic map, we propose the image encryption and compression algorithm in which the 2D phased linear chaotic map is integrated with Chinese remainder theorem. The original image is permutated by 2D phased linear chaotic map; then the permuted image is synchronously diffused and compressed by the compression ration generated by Chinese remainder theorem. At last we use MATLAB simulation platform to test this algorithm, and the result show that it has excellent performance in encryp- tion and compression, the compression ratio produced is very stable, and the diffusion mechanism is highly secure, the key space is also large enough, thus the anti-attack performance improves significantly.