Optimizing the iterative reprojection phase retrieval algorithm Via Angle sampling

Coherence-based imaging with synchrotron radiation offers spatial resolutions beyond the limits of conventional X-ray imaging and enables quantitative mapping of the refractive index. In nanotomography experiments with phase contrast, reconstruction is commonly performed in a two-step procedure, namely phase retrieval and computer tomography. One may enforce a 3D consistency constraint by repeatedly switching between both steps through a reprojection of the tomogram, which comes at a high computational cost. In this study, we accelerate the reprojection approach by updating the phase retrieval step on a subset of the projection angles. We show that the improvement is also reflected on the rest of angles through the tomographic reconstruction. We present an exemplary phantom to show that the angle sampling both accelerates convergence and helps reconstruction of challenging angles.

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DDC Class

600: Technology