Optical Hierarchical Image Encryption by Use of Iterative Fourier Transform Algorithm
Yang Yong-bin · Chinese Journal of Lasers · 2006
A novel approach-multiple phase encoding for hierarchical security by use of a 4f optical system and iterative Fourier transform algorithm(IFTA) is presented,which is based on the methodology of virtual optics.Two or more phase masks produced by multiple IFTA are used in this hierarchical security system,in which different target images can be retrieved by use of different numbers of phase masks.The more numbers of phase masks the user has,the more images he can get.In addition to numbers of the phase masks,the sequential order of the phase masks is introduced to increase the system security.Simulation results are demonstrated to verify the proposed method.