Propagation-based phase retrieval using the contrast transfer function (CTF) allows images at any propagation distance to be used when recovering the phase of slowly-varying objects. The CTF suffers from artifacts due to nulls in the transfer function at low spatial frequency and at higher, propagation-distance-dependent frequencies, though the latter can be alleviated by combining measurements at multiple distances. We demonstrate that the use of extended sources can improve low frequency performance. In addition, this method offers source shape as a parameter that can be used when optimizing combinations of measurements to produce robust phase reconstructions.

Date Published: 1 May 2017
PDF: 8 pages
Proc. SPIE 10222, Computational Imaging II, 102220R (1 May 2017); doi: 10.1117/12.2262692

Published in SPIE Proceedings Vol. 10222:
Computational Imaging II
Abhijit Mahalanobis; Amit Ashok; Lei Tian; Jonathan C. Petruccelli; Kenneth S. Kubala, Editor(s)