级联相位恢复算法用于光学图像加密

提出用级联相位恢复算法把待加密图像综合到2块随机相位板(RPM)之中从而实现图像加密的技术。该算法利用同时调整2块RPM的相位分布的搜索策略，扩大搜索空间，能得到质量非常高的解密图像。计算机模拟结果表明，该算法的收敛速度很快，能迅速找到非常好的近似解；只有当2块RPM互相匹配时才能得到解密图像，使系统获得很高的安全性。

A Cascaded-phases Retrieval Algorithm for Optical Image Encryption

A cascaded-phases retrieval algorithm that synthesizes the target image into two random phase-masks(RPM) was proposed for image encryption.This proposed algorithm employs a searching strategy that modifies both the distributions of the two RPM simultaneously to enlarge the searching space.Consequently,a retrieved image with significantly high quality was obtained.Computer simulation results show that the algorithm converges rapidly,that is,the closely optimized solution can be found very quickly.The significant image can be obtained only when the designed RPM are matched and each of them is located into the proper plane in the 4-f architecture.This character may introduce a high level of security.