Abstract

This paper presents an alternative approach for image refocusing in digital Fresnel holography. In literature, a large majority of reported focus detection criteria is based on amplitude contrast or phase contrast. We propose a new focus detection criterion based on the speckle phase coherence factor. Robust noise probability density is estimated from anisotropic diffusion. Estimation of the coherence factor is then obtained from a least square fit. Experimental results show the suitability of the proposed approach for accurate image plane refocusing.

© 2016 Optical Society of America