no code implementations • 27 Feb 2023 • Wenrui Li, Venkatesh Sridhar, K. Aditya Mohan, Saransh Singh, Jean-Baptiste Forien, Xin Liu, Gregery T. Buzzard, Charles A. Bouman
As computational tools for X-ray computed tomography (CT) become more quantitatively accurate, knowledge of the source-detector spectral response is critical for quantitative system-independent reconstruction and material characterization capabilities.
no code implementations • 27 Feb 2023 • Mohammad Samin Nur Chowdhury, Diyu Yang, Shimin Tang, Singanallur V. Venkatakrishnan, Hassina Z. Bilheux, Gregery T. Buzzard, Charles A. Bouman
The algorithm estimates the linear attenuation coefficient spectra from the measured radiographs and then uses these spectra to perform polycrystalline material decomposition and reconstructs 3D material volumes to localize materials in the spatial domain.
no code implementations • 9 Feb 2023 • Abdulrahman M. Alanazi, Singanallur Venkatakrishnan, Gregery T. Buzzard, Charles A. Bouman
Our approach integrates a physics-based forward model that accounts for the propagation of a collimated ultrasonic beam in multi-layered media, a spatially varying image prior, and a denoiser designed to suppress the ringing artifacts that are characteristic of reconstructions from high-fractional bandwidth ultrasound sensor data.
no code implementations • 1 Dec 2022 • Diyu Yang, Shimin Tang, Singanallur V. Venkatakrishnan, Mohammad S. N. Chowdhury, Yuxuan Zhang, Hassina Z. Bilheux, Gregery T. Buzzard, Charles A. Bouman
Neutron computed tomography (nCT) is a 3D characterization technique used to image the internal morphology or chemical composition of samples in biology and materials sciences.
no code implementations • 29 Nov 2022 • Abdulrahman M. Alanazi, Singanallur Venkatakrishnan, Hector Santos-Villalobos, Gregery T. Buzzard, Charles Bouman
Collimated beam ultrasound systems are a technology for imaging inside multi-layered structures such as geothermal wells.
no code implementations • 15 Sep 2022 • Diyu Yang, Craig A. J. Kemp, Gregery T. Buzzard, Charles A. Bouman
In this paper, we present Multi-Pose Fusion, a novel algorithm that performs a joint tomographic reconstruction from CT scans acquired from multiple poses of a single object, where each pose has a distinct rotation axis.
no code implementations • 31 Mar 2022 • Ulugbek S. Kamilov, Charles A. Bouman, Gregery T. Buzzard, Brendt Wohlberg
Plug-and-Play Priors (PnP) is one of the most widely-used frameworks for solving computational imaging problems through the integration of physical models and learned models.
no code implementations • 9 Dec 2021 • Wenrui Li, Gregery T. Buzzard, Charles A. Bouman
Sparse-view CT reconstruction is important in a wide range of applications due to limitations on cost, acquisition time, or dosage.
no code implementations • 28 Nov 2021 • Qiuchen Zhai, Brendt Wohlberg, Gregery T. Buzzard, Charles A. Bouman
Ptychography is a computational imaging technique using multiple, overlapping, coherently illuminated snapshots to achieve nanometer resolution by solving a nonlinear phase-field recovery problem.
no code implementations • 1 Aug 2020 • Soumendu Majee, Thilo Balke, Craig A. J. Kemp, Gregery T. Buzzard, Charles A. Bouman
In this paper, we present multi-slice fusion, a novel algorithm for 4D reconstruction, based on the fusion of multiple low-dimensional denoisers.
no code implementations • 3 Jul 2019 • Ankush Chakrabarty, Devesh K. Jha, Gregery T. Buzzard, Yebin Wang, Kyriakos Vamvoudakis
We develop a method for obtaining safe initial policies for reinforcement learning via approximate dynamic programming (ADP) techniques for uncertain systems evolving with discrete-time dynamics.
no code implementations • 15 Jun 2019 • Soumendu Majee, Thilo Balke, Craig A. J. Kemp, Gregery T. Buzzard, Charles A. Bouman
In this paper, we present Multi-Slice Fusion, a novel algorithm for 4D and higher-dimensional reconstruction, based on the fusion of multiple low-dimensional denoisers.
no code implementations • 20 Mar 2019 • Rizwan Ahmad, Charles A. Bouman, Gregery T. Buzzard, Stanley Chan, Sizhou Liu, Edward T. Reehorst, Philip Schniter
In this article, we describe the use of "plug-and-play" (PnP) algorithms for MRI image recovery.
no code implementations • 6 Jul 2018 • Dong Hye Ye, Gregery T. Buzzard, Max Ruby, Charles A. Bouman
Filtered back projection (FBP) is a classical method for image reconstruction from sinogram CT data.
no code implementations • 24 May 2017 • Gregery T. Buzzard, Stanley H. Chan, Suhas Sreehari, Charles A. Bouman
We give examples to illustrate consensus equilibrium and the convergence properties of these algorithms and demonstrate this method on some toy problems and on a denoising example in which we use an array of convolutional neural network denoisers, none of which is tuned to match the noise level in a noisy image but which in consensus can achieve a better result than any of them individually.
no code implementations • 14 Mar 2017 • G. M. Dilshan P. Godaliyadda, Dong Hye Ye, Michael D. Uchic, Michael A. Groeber, Gregery T. Buzzard, Charles A. Bouman
In each step of SLADS, the objective is to find the pixel that maximizes the expected reduction in distortion (ERD) given previous measurements.