A phase recovery image reproduction method for lensless imaging

Abstract

The invention provides a phase recovery image reproduction method for lensless imaging, Fast power spectra were captured by the experimental device of coherent diffraction imaging, the imaging devicerequires only one collimated beam-spreading laser, A Fourier lens and a CCD detector, the detected power spectrum is reconstructed in three steps, the first step is to calculate an initial phase by using a hybrid input-output algorithm, Soft aperture scanning is then performed, instead of scanning in the target plane and the spatial spectral plane, The second step combines the Ptychography algorithm to enhance the Fourier domain constraints, and uses the phase iterative restoration algorithm to achieve the reconstruction of the target image. In the third step, in order to further reduce the normalized root mean square error, the error reduction algorithm is used to reconstruct the target image. The imaging device of the invention is simple, and the algorithm can quickly reconstruct an accurate target image from a power spectrum diagram, thereby realizing the function of image reproduction.

Description

technical field [0001] The invention relates to the field of coherent diffraction imaging, in particular to a phase recovery image reproduction method for lensless imaging. Background technique [0002] In practical situations, the image directly measured is often only the intensity distribution of the wave field, and the phase distribution of the wave field is often difficult to measure directly, or even impossible. Therefore, recovering phase information from intensity measurement data has been researched in recent years. The hotspot, phase recovery algorithm is such a method of deriving the amplitude and phase of the radiation source from the intensity measurement data. [0003] At present, there are two commonly used phase recovery methods, one is to use a phase difference sensor (specifically, a wavefront sensor can be used) to directly detect the phase difference of the optical system, and the other is to use the Gerchberg–Saxton (GS) algorithm to The optimal theoreti...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problems existing in the prior art, the present invention proposes a phase recovery image reproduction method without lens imaging, which solves the diffraction limit problem encountered in the construction of the optical system in the prior art, and also solves the stagnation of the IFT algorithm in the iterative process. The problem that a certain local minimum value cannot restore the target image has achieved the effect of simple and easy to operate experimental equipment, less computing time in the iterative process, and a clear restored target

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