Compressive Ptychography using Deep Image and Generative Priors
This work addresses a bottleneck in ptychography for applications like defense and materials science, offering an incremental improvement over existing methods.
The paper tackles the problem of long data acquisition times in ptychography by reducing scan points, which causes artifacts and distortions, and proposes a generative model combining deep image and generative priors to improve reconstruction accuracy, demonstrating enhanced results compared to state-of-the-art methods in numerical experiments.
Ptychography is a well-established coherent diffraction imaging technique that enables non-invasive imaging of samples at a nanometer scale. It has been extensively used in various areas such as the defense industry or materials science. One major limitation of ptychography is the long data acquisition time due to mechanical scanning of the sample; therefore, approaches to reduce the scan points are highly desired. However, reconstructions with less number of scan points lead to imaging artifacts and significant distortions, hindering a quantitative evaluation of the results. To address this bottleneck, we propose a generative model combining deep image priors with deep generative priors. The self-training approach optimizes the deep generative neural network to create a solution for a given dataset. We complement our approach with a prior acquired from a previously trained discriminator network to avoid a possible divergence from the desired output caused by the noise in the measurements. We also suggest using the total variation as a complementary before combat artifacts due to measurement noise. We analyze our approach with numerical experiments through different probe overlap percentages and varying noise levels. We also demonstrate improved reconstruction accuracy compared to the state-of-the-art method and discuss the advantages and disadvantages of our approach.