Alexander Ditter

2papers

2 Papers

58.1LGMay 1
Machine Learning-Augmented Acceleration of Iterative Ptychographic Reconstruction

Bowen Zheng, Katayun Kamdin, David Shapiro et al.

Iterative ptychographic reconstruction algorithms are widely used for coherent diffractive imaging but can exhibit slow convergence under realistic experimental conditions. We propose a machine learning-augmented approach that accelerates iterative ptychographic reconstruction by introducing a learned fast-forward operator applied during reconstruction. Following an initial warm-up using standard iterations, the fast-forward operator advances the reconstruction toward a more converged state, after which conventional iterative updates are resumed. This strategy preserves the physical consistency and flexibility of established ptychographic solvers while reducing the number of iterations required for convergence. The model is trained on diverse ptychographic datasets and evaluated on experimental data acquired in a different year, demonstrating robustness and temporal generalization. Compared with conventional iterative solvers, the machine learning-augmented method achieves comparable reconstruction quality while converging faster in terms of Poisson negative log-likelihood, yielding over a two-fold reduction in wall-clock time. The approach has been integrated into an existing reconstruction pipeline and deployed in production at a synchrotron beamline, demonstrating practicality for real-time experimental operation.

SEAug 28, 2015
OpenCL 2.0 for FPGAs using OCLAcc

Franz Richter-Gottfried, Alexander Ditter, Dietmar Fey

Designing hardware is a time-consuming and complex process. Realization of both, embedded and high-performance applications can benefit from a design process on a higher level of abstraction. This helps to reduce development time and allows to iteratively test and optimize the hardware design during development, as common in software development. We present our tool, OCLAcc, which allows the generation of entire FPGA-based hardware accelerators from OpenCL and discuss the major novelties of OpenCL 2.0 and how they can be realized in hardware using OCLAcc.