Using sparsity information for iterative phase retrieval in x-ray propagation imaging.
Citable Link (URL):http://resolver.sub.uni-goettingen.de/purl?gs-1/13481
First published (peer reviewed)
Optics express 2016; 24(8) p.8332-8343
For iterative phase retrieval algorithms in near field x-ray propagation imaging experiments with a single distance measurement, it is indispensable to have a strong constraint based on a priori information about the specimen; for example, information about the specimen's support. Recently, Loock and Plonka proposed to use the a priori information that the exit wave is sparsely represented in a certain directional representation system, a so-called shearlet system. In this work, we extend this approach to complex-valued signals by applying the new shearlet constraint to amplitude and phase separately. Further, we demonstrate its applicability to experimental data.