Showing papers by "Guohai Situ published in 2003"
TL;DR: A cascaded iterative Fourier transform (CIFT) algorithm is presented for optical security applications that employs an improved searching strategy: modifying the phase-distributions of both masks synchronously as well as enlarging the searching space.
55 citations
TL;DR: In this paper, a cascaded iterative Fourier transform (CIFT) algorithm is presented for optical security applications, where two phasemasks are designed and located in the input and the Fourier domains of a 4-f correlator respectively, in order to implement the optical encryption or authenticity verification.
Abstract: A cascaded iterative Fourier transform (CIFT) algorithm is presented for optical security applications. Two phase-masks are designed and located in the input and the Fourier domains of a 4-f correlator respectively, in order to implement the optical encryption or authenticity verification. Compared with previous methods, the proposed algorithm employs an improved searching strategy: modifying the phase-distributions of both masks synchronously as well as enlarging the searching space. Computer simulations show that the algorithm results in much faster convergence and better image quality for the recovered image. Each of these masks is assigned to different person. Therefore, the decrypted image can be obtained only when all these masks are under authorization. This key-assignment strategy may reduce the risk of being intruded.
4 citations