基于光学干涉及矢量合成方法的图像加密技术研究

According to the research status of optical image encryption based on the two-beam interference, this project applied the rotating vector diagram of optics to optical image encryption, amplitude and phase parts of the image complex information embodied in the amplitude vector length and the rotation angle, and the image encryption and decryption based on multi-beam interference is completed by the vector synthesis and decomposition. According to the fact that the amplitude and phase information reflects amplitude plate with certain transmittance and phase plate in optics, the image encryption and decryption can be achieved through the design of certain spatial light modulators. The first part of the specific research content is that a plurality of unit vector synthesis can realize the image encryption and decryption based on multi-beam interference, but the general vector (not necessarily a unit vector) synthesis can achieve the synthesis encoding with color and gray images. In addition, interference theory combined with the amplitude phase truncation technology and iteration method can get an effect encoding technology. Finally, several methods are put forward to solve the problem of image profile of the encoding system. We hope that more new technology for the optical image encryption can be presented through the research of this project, the application scope of interference and diffraction theory can be expanded, and better research methods can be provided for the field of optical, medical and digital image processing.

本课题根据基于双束光干涉的光学图像编码的研究状况，将波动光学中的旋转矢量图法用于光学图像加密，图像复振幅信息中的振幅和相位信息体现为振幅矢量的长度和旋转角度，通过矢量的合成和分解，完成多光束干涉图像加密解密。根据光学中振幅和相位信息体现为一定透过率的振幅板和相位板的事实，拟设计空间光调制器实现图像的加密和解密。具体拟研究基于多个单位矢量的合成实现多光束干涉的图像加密解密，基于任意矢量（不一定单位矢量）的合成实现彩色灰度图像综合编码，并结合干涉理论、振幅相位截取技术，迭代循环方法等研究高效的编码技术，提出消除干涉编码中出现的轮廓问题。希望通过本项目的研究可以为光学图像加密领域提出更多的新技术，拓展干涉衍射理论的应用范围，为光学、医学及数字图像处理领域提供更好的研究方法。

项目研究内容紧紧围绕着申请书的主要内容，开展研究多光束干涉和旋转矢量图法的光学图像编码方法，解决基于干涉理论图像编码方法的轮廓再现问题，并对编码方法进行安全性验证研究。提出一种基于相干叠加和非等模分解的非对称光学加密系统；提出基于多光束干涉和一般矢量分解的光学图像加密技术；提出基于菲涅尔衍射与相位恢复算法的彩色图像加密技术，提出一种新的双图像变换光学加密系统；并对基于压缩感知和多图像像素交叉区域移位法的图像加密技术及基于叠层衍射和JTC系统的图像加密方法进行了初步研究。通过利用普通矢量分解的方法，可以产生互不相同的四个振幅和相位掩膜，大大地增强了系统的安全性，解决了加密系统的轮廓再现问题。计算机模拟结果证实了这些方法的可行性和有效性。