We develop a speckle-tracking method for x-ray phase-contrast imaging, based on the concept of geometric flow. This flow is a conserved current associated with deformation of illuminating x-ray speckles induced by passage through a sample. The method provides a rapid, efficient, and accurate algorithm for quantitative phase imaging. It is highly photon efficient and able to image dynamic objects, since a single radiograph of the sample is sufficient for the phase recovery. We experimentally quantify the resolution and contrast of the approach with both two-dimensional and three-dimensional phase-imaging applications using x-ray synchrotron radiation. Finally, we discuss adaptations of the method to imaging with compact x-ray sources that have a large source size and significant spectral bandwidth.
@article{arxiv.1808.00456,
title = {Single-Image Geometric-Flow X-Ray Speckle Tracking},
author = {David M. Paganin and Helene Labriet and Emmanuel Brun and Sebastien Berujon},
journal= {arXiv preprint arXiv:1808.00456},
year = {2018}
}