Open AccessIncorporation of an experimentally determined MTF for spatial frequency filtering and deconvolution during optical projection tomography reconstruction
Author(s) -
Lingling Chen,
James McGinty,
Harriet B. Taylor,
Laurence Bugeon,
Jonathan R. Lamb,
Margaret J. Dallman,
Paul M. W. French
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.007323
Subject(s) - optics , optical transfer function , deconvolution , spatial frequency , point spread function , iterative reconstruction , image quality , projection (relational algebra) , spatial light modulator , physics , tomography , image resolution , filter (signal processing) , computer science , computer vision , algorithm , image (mathematics)
We demonstrate two techniques to improve the quality of reconstructed optical projection tomography (OPT) images using the modulation transfer function (MTF) as a function of defocus experimentally determined from tilted knife-edge measurements. The first employs a 2-D binary filter based on the MTF frequency cut-off as an additional filter during back-projection reconstruction that restricts the high frequency information to the region around the focal plane and progressively decreases the spatial frequency bandwidth with defocus. This helps to suppress "streak" artifacts in OPT data acquired at reduced angular sampling, thereby facilitating faster OPT acquisitions. This method is shown to reduce the average background by approximately 72% for an NA of 0.09 and by approximately 38% for an NA of 0.07 compared to standard filtered back-projection. As a biological illustration, a Fli:GFP transgenic zebrafish embryo (3 days post-fertilisation) was imaged to demonstrate the improved imaging speed (a quarter of the acquisition time). The second method uses the MTF to produce an appropriate deconvolution filter that can be used to correct for the spatial frequency modulation applied by the imaging system.