title: Using sparsity information for iterative phase retrieval in x-ray propagation imaging.
abstract: 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.
authors.forename: A
authors.initials: A
authors.lastname: Pein
authors.forename: S
authors.initials: S
authors.lastname: Loock
authors.forename: G
authors.initials: G
authors.lastname: Plonka
authors.forename: T
authors.initials: T
authors.lastname: Salditt