In this paper, we present a circularly symmetric point spread function (PSF) estimation technique for a fully digital autofocusing
system. The proposed algorithm provides realistic, unsupervised PSF estimation by establishing the relationship
between the one-dimensional ideal step response and the corresponding two-dimensional circularly symmetric PSF.
Main advantage of the proposed algorithm is the accurate estimation of the PSF combining by using interpolation,
feasible step response estimation. The proposed estimation method will serve as (i) a fundamental procedure in designing
an in-house extended depth-of-field (EDoF) system, (ii) a detecting method for improperly manufactured imaging
sensors in the production line, and (iii) a PSF estimation method for general image restoration algorithms.