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We present an alternative numerical reconstruction algorithm for direct tomographic reconstruction of a sample refractive indices from the measured intensities of its far-field coherent diffraction patterns. We formulate the well-known…

Computational Physics · Physics 2019-02-06 T. Ramos , Bastian E. Grønager , Martin Skovgaard Andersen , J. W. Andreasen

In this paper, we study a 2D tomography problem for point source models with random unknown view angles. Rather than recovering the projection angles, we reconstruct the model through a set of rotation-invariant features that are estimated…

Signal Processing · Electrical Eng. & Systems 2018-11-27 Mona Zehni , Shuai Huang , Ivan Dokmanić , Zhizhen Zhao

Predicting measurement outcomes from an underlying structure often follows directly from fundamental physical principles. However, a fundamental challenge is posed when trying to solve the inverse problem of inferring the underlying…

The regularized D-bar method is a popular method for solving Electrical Impedance Tomography (EIT) problems due to its efficiency and simplicity. It utilizes the low-pass truncated scattering data in the non-linear Fourier domain to solve…

Numerical Analysis · Mathematics 2025-02-10 Xiang Cao , Qiaoqiao Ding , Xiaoqun Zhang

Speckle suppression in synthetic aperture radar (SAR) images is a key processing step which continues to be a research topic. A wide variety of methods, using either spatially-based approaches or transform-based strategies, have been…

Computer Vision and Pattern Recognition · Computer Science 2024-08-30 Alejandro Mestre-Quereda , Juan M. Lopez-Sanchez

Diffusion models have recently emerged as a powerful technique in image generation, especially for image super-resolution tasks. While 2D diffusion models significantly enhance the resolution of individual images, existing diffusion-based…

Computer Vision and Pattern Recognition · Computer Science 2024-11-27 Bohao Chen , Yanchao Zhang , Yanan Lv , Hua Han , Xi Chen

Microstructure reconstruction is an important cornerstone to the inverse materials design concept. In this work, a general algorithm is developed to reconstruct a three-dimensional microstructure from given descriptors. Based on…

Materials Science · Physics 2021-10-26 Paul Seibert , Alexander Raßloff , Marreddy Ambati , Markus Kästner

Ultrasound Tomography has seen a revival of interest in the past decade, especially for breast imaging, due to improvements in both ultrasound and computing hardware. In particular, three-dimensional ultrasound tomography, a fully…

Computational Physics · Physics 2020-05-27 Ashkan Javaherian , Felix Lucka , Ben Cox

This work implements and numerically tests the direct reconstruction algorithm introduced in [Garde & Hyv\"onen, SIAM J. Math. Anal., 2024] for two-dimensional linearized electrical impedance tomography. Although the algorithm was…

Numerical Analysis · Mathematics 2026-02-18 Antti Autio , Henrik Garde , Markus Hirvensalo , Nuutti Hyvönen

We demonstrate a motion-free intensity diffraction tomography technique that enables direct inversion of 3D phase and absorption from intensity-only measurements for weakly scattering samples. We derive a novel linear forward model,…

Image and Video Processing · Electrical Eng. & Systems 2018-06-26 Ruilong Ling , Waleed Tahir , Hsing-Ying Lin , Hakho Lee , Lei Tian

Deep learning methods for accelerated MRI achieve state-of-the-art results but largely ignore additional speedups possible with noncartesian sampling trajectories. To address this gap, we created a generative diffusion model-based…

Artificial Intelligence · Computer Science 2024-10-02 Trevor J. Chan , Chamith S. Rajapakse

We present a new method for constructing three-dimensional mass maps from gravitational lensing shear data. We solve the lensing inversion problem using truncation of singular values (within the context of generalized least squares…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Jake VanderPlas , Andrew Connolly , Bhuvnesh Jain , Mike Jarvis

Radio-frequency dosimetry is an important process in human safety and for compliance of related products. Recently, computational human models generated from medical images have often been used for such assessment, especially to consider…

Machine Learning · Computer Science 2020-04-29 Essam A. Rashed , Yinliang Diao , Akimasa Hirata

Ground-based solar image restoration is a computationally expensive procedure that involves nonlinear optimization techniques. The presence of atmospheric turbulence produces perturbations in individual images that make it necessary to…

Instrumentation and Methods for Astrophysics · Physics 2023-07-26 A. Asensio Ramos , S. Esteban Pozuelo , C. Kuckein

Deep learning-based models have demonstrated remarkable success in solving illposed inverse problems; however, many fail to strictly adhere to the physical constraints imposed by the measurement process. In this work, we introduce a…

Machine Learning · Computer Science 2025-05-22 Jorge Bacca

While data has certainly taken the center stage in computer vision in recent years, it can still be difficult to obtain in certain scenarios. In particular, acquiring ground truth 3D shapes of objects pictured in 2D images remains a…

Computer Vision and Pattern Recognition · Computer Science 2016-08-02 Joao Carreira , Sara Vicente , Lourdes Agapito , Jorge Batista

We propose an approach to 3D reconstruction via inverse procedural modeling and investigate two variants of this approach. The first option consists in the fitting set of input parameters using a genetic algorithm. We demonstrate the…

Graphics · Computer Science 2023-10-23 Albert Garifullin , Nikolay Maiorov , Vladimir Frolov

Efficient and high-fidelity prior sampling and inversion for complex geological media is still a largely unsolved challenge. Here, we use a deep neural network of the variational autoencoder type to construct a parametric low-dimensional…

Machine Learning · Statistics 2017-10-26 Eric Laloy , Romain Hérault , John Lee , Diederik Jacques , Niklas Linde

Computed tomography has propelled scientific advances in fields from biology to materials science. This technology allows for the elucidation of 3-dimensional internal structure by the attenuation of x-rays through an object at different…

Computer Vision and Pattern Recognition · Computer Science 2022-11-02 Rey Mendoza , Minh Nguyen , Judith Weng Zhu , Vincent Dumont , Talita Perciano , Juliane Mueller , Vidya Ganapati

The Regularized D-bar method for Electrical Impedance Tomography provides a rigorous mathematical approach for solving the full nonlinear inverse problem directly, i.e. without iterations. It is based on a low-pass filtering in the…

Numerical Analysis · Mathematics 2015-06-19 Sarah Hamilton , Juan Manuel Reyes , Samuli Siltanen , Xiaoqun Zhang