Open AccessImproved particle size estimation in digital holography via sign matched filtering
Author(s) -
Jiang Lu,
Raymond A. Shaw,
Weidong Yang
Publication year - 2012
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.012666
Subject(s) - optics , holography , pixel , noise (video) , digital holography , particle size , particle (ecology) , filter (signal processing) , fourier transform , range (aeronautics) , materials science , physics , computer science , computer vision , image (mathematics) , chemistry , oceanography , composite material , quantum mechanics , geology
A matched filter method is provided for obtaining improved particle size estimates from digital in-line holograms. This improvement is relative to conventional reconstruction and pixel counting methods for particle size estimation, which is greatly limited by the CCD camera pixel size. The proposed method is based on iterative application of a sign matched filter in the Fourier domain, with sign meaning the matched filter takes values of ±1 depending on the sign of the angular spectrum of the particle aperture function. Using simulated data the method is demonstrated to work for particle diameters several times the pixel size. Holograms of piezoelectrically generated water droplets taken in the laboratory show greatly improved particle size measurements. The method is robust to additive noise and can be applied to real holograms over a wide range of matched-filter particle sizes.