https://www.math.ucdavis.edu/~fannjiang/
Thu, June 10, 2021, 9:00-10:00 am PDT via Zoom
Title: Ptychography: Theory and Algorithms.
Abstract:
Ptychography is a scanning version of coded-aperture phase retrieval, a versatile method that finds its way to many applications in molecular and materials imaging. Its operating principle is that measurement redundancy due to overlap of scanning probe removes the usual ambiguities in standard phase retrieval by providing extra constraint for unique characterization of the underlying extended object.
A remarkable effect of ptychography emerged in physics experiments more than 10 years ago that the coded aperture can be recovered along with the unknown object, up to a constant phase factor, for certain measurement schemes with sufficient probe overlap (i.e. blind ptychography). We review recent progress in mathematical theory and algorithms developed for blind ptychography operating at realistic level of measurement resources.