以单幅衍射强度图像为密文的光学衍射成像加密系统  

Optical Image Encryption with Ciphertext of a Single Diffraction Intensity Pattern

作　　者：白音布和 李根全[2] 吕林霞[2] 秦怡[2] 

机构地区：[1]通辽职业学院机电工程学院,内蒙古通辽028000 [2]南阳师范学院物理与电子工程学院,河南南阳473061

出　　处：《激光与光电子学进展》2014年第10期62-68,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(10947020);南阳师范学院青年基金(QN2014016)

摘　　要：提出了一种基于光学衍射成像原理的图像加密方法,并以具有两个随机相位板的自由空间衍射结构为例,说明该方法的原理。该系统加密过程简单,加密过程只需要记录一幅衍射强度图像,即作为密文保存。为了从密文中完全恢复明文,需要除了3个相位板之外的第四个密钥,即原始图像的稀疏数据。这需要在对原始图像加密之前,利用数字方法提取其稀疏数据。在利用相位恢复算法恢复明文的过程中,这些稀疏数据作为输入平面的部分振幅支撑,可以避免迭代过程的停滞问题并提高收敛速率,从而完全恢复明文。由于完成加密过程只需要记录单幅强度图像,避免了干涉装置,提高了记录效率,较大地方便了密文的传输。计算机模拟结果证实了本方法的有效性。A novel method for image encryption by employing the diffraction imaging technique is proposed. This method is in principle suitable for most of the diffractive-imaging-based optical encryption schemes, and the classical double random phase encoding in the Fresnel domain is taken for an example for illustrating it. The encryption process is rather simple because only a single diffraction intensity pattern is needed to be recorded. The security keys include, in addition to the two phase only masks in the input and the Fresnel plane, the sparse data of the plaintext that can be obtained with a simple digital means. The sparse data serve as partial input plane support constraint in a phase retrieval algorithm, which is employed for completely retrieving the plaintext. Simulation results are presented to verify the validity of the proposed approach.

关 键 词：图像处理 光学图像加密 衍射成像 稀疏数据 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置]