Optical color-image verification using multiple-pinhole phase retrieval

We propose a multiple-pinhole phase retrieval algorithm to generate an intermediate modulated wavefront for optical color-image verification. Since an incomplete but modulated wavefront is extracted in the intermediate optical path, the reconstructed objects will contain noise-like signals and do not visually render specimen information. Nonlinear optical correlation is further conducted to verify the recovered objects. The performance of the setup parameters and robustness of the proposed method are also illustrated. It is found that pinhole patterns placed in the intermediate optical path not only serve as the constraints for the developed phase retrieval algorithm, but also can provide a channel to modulate noise-like images obtained in the object plane during the recovery.