基于傅里叶叠层成像的光学图像加密

Optical image encryption based on Fourier ptychography

提出一种基于傅里叶叠层成像的光学图像加密技术.基于传统的4f双随机相位编码系统,将滤波孔径(探针)紧贴着随机相位掩模板放置在傅里叶频谱面上,在频域限制不同成分的空间频率信息通过.该技术采用低数值孔径的透镜和平行光多角度照明,使装置更加简单.计算机模拟结果表明,该技术收敛速度快,可行性较强,并具有高鲁棒性、高安全性和高解密质量等优点.

We propose a method for optical image encryption based on Fourier ptychography （FP）. On the basis of 4f double random phase encoding system, the filter aperture （probe） is placed at the Fourier plane, so that the object support constrains for phase retrieval of FP are imposed by the confined optical-transfer-functions in the Fourier domain. Furthermore, we adopt the low numerical aperture objective lens and the variable-angle illumination, which simplifies the device effectively. Numerical simulation results show that the method has the merits of high convergence speed, feasibility, robustness, decryption quality,and security.