PyNX is a toolkit with assorted Python modules and command-line scripts which can be used for the analysis and simulation of coherent X-ray imaging, including techniques such as coherent diffraction imaging, ptychography and wavefront propagation, in the near- or far-field regime. All calculations can be executed solely on graphical processing units (GPUs) for accelerated computing. Elementary algorithms can be easily tailored, built upon and combined using an operator-based approach, allowing full flexibility with high-performance computing. Calculations can be distributed on multiple GPUs using MPI, e.g. for large ptychography data sets.

An application of the Scale-Invariant Feature Transform (SIFT) algorithm for image stack alignment in full-field X-ray absorption spectroscopy is described and a Python-OpenCL implementation of this algorithm is presented.

The formalism of iterative tomographic reconstruction with sparsity inducing penalty is extended to enable ring artifacts correction.

A method for reducing the cupping effect in local tomography based on a known region is proposed.