title: A two-stage method to correct aberrations induced by slide slant in bright-field microscopy.
abstract: To achieve optimal image quality in bright field microscopy, the slide surface should be perpendicular to the optical axis of the microscope. However, in the recently proposed "slanted scan" slide acquisition technique, scan speed is increased by purposely slanting the slide by a small angle (of 3-5°) so that multiple focal depths can be imaged simultaneously. In this case, the slanted slide introduces a bend in the point spread function (PSF), resulting in a coma and other aberrations that degrade image quality. In this paper, we propose a two-stage deconvolution method specifically designed to correct the aberrations induced by a slanted scan, but with general applicability to high-resolution bright-field microscopy. Specifically, we initially apply phase deconvolution to correct the dominating coma aberration, before applying a conventional semi-blind deconvolution method to further improve image resolution and contrast. We also propose a novel method to estimate the degree of coma aberration and the PSF of the optics utilising actual cytology specimens. The efficacy of the proposed algorithm is demonstrated quantitatively on simulated data, against a ground-truth (object) image, and qualitatively on cervical cytology specimens. Results demonstrate both improved convergence speed of the two-stage approach, especially when correcting the bend in the PSF, and a resultant image quality that is comparable to a conventionally (flat) scanned specimen.
authors.affiliation: The University of Queensland, School of Information Technology and Electrical Engineering, St Lucia, QLD 4072, Australia. Electronic address: y.fan3@uq.edu.au.
authors.forename: Yilun
authors.initials: Y
authors.lastname: Fan
authors.affiliation: The University of Queensland, School of Information Technology and Electrical Engineering, St Lucia, QLD 4072, Australia.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Bradley
keywords: Coma aberration; Phase deconvolution; Tilted plane parallel plate; Virtual microscopy