双随机相位不对称分数傅里叶变换计算全息

提出了双随机相位不对称分数傅里叶变换计算全息.首先用一随机相位函数乘以输入图像信息,然后沿x方向实施α级次的一维分数傅里叶变换,再乘以第2个随机相位函数,最后沿y方向实施β级次的一维分数傅里叶变换.采用迂回位相编码法对变换后的结果编码,绘出计算全息图.为了恢复原图像,需要知道变换级次和随机相位函数.利用这种方法进行图像加密,使加密图像的密钥由原来两重增加到四重,从而提高了系统的保密性能.

Double random phase computer generated hologram of asymmetry fractional Fourier transform

A new optical encryption technique based on double random phase computer-generated hologram of asymmetry fractional Fourier transform is presented.In this method,two phase functions are introduced into the input image and its fractional domain spectrum before the fractional Fourier transform hologram of original object of different order in the x and y directions.The transformed result is coded and fabricated into computer-generated hologram.In order to reconstruct the encoded image,two random functions and two orders must be matched.Because the decoding keys are added to four from two,anti-counterfeiting intensity can be improved greatly when it is used to encrypt image or anti-counterfeit.