Phase retrieval algorithms based on 4-f system for optical image
encryption are compared in respect of the image retrieval quality
and the convergence. Simulation results show that enlarging the
searching space can decrypt the image with extremely high quality,
while employing the searching strategy of modifying both the
phase-distributions in the input and the frequency planes can
result in much faster convergence for the algorithm.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.