双幅数字图象加密的实值编码研究

Research On The Real-Value Encryption For Double Digital Images

本文提出了一种双幅数字图象加密的实值编码方法,待加密的两幅数字图象扩大一倍,然后后与一个随机相位掩膜一起通过光学透镜作傅立叶变换,取其实部作为编码图象。利用全息记录的方法解码,即已编码的图象和随机相位掩膜的傅立叶变换相加通过光学透镜作傅立叶反变换,记录反变换的光强分布,再通过非线性变换或灰度变换的方法町以恢复原图象。该加密编码方法简单,町以同时对两幅图象编码,而且得到实值的编码图象,便于数字图象的记录、存储与输出。

A real- value encryption and decryption method of double digital images is proposed for the optical seonity system, Two full- phase images to be encrypted are enlarged and together with a random phase mask are Fourier transformed . Real part of the result is used as an encrypted image. The addition of encrypted image and the Fourier transformed of the random phase is inverse - Fourier transfomed. The intensity values of inverse - Fourier transfomed image is adjusted. It＇s upside gives the exact original double images. The method of encryption and decryption is simply performed for double digital images and encryted image is real- valued tree.It is convenient for digital images to print, store or display.