no code implementations • 20 Dec 2023 • Rafael Orozco, Philipp Witte, Mathias Louboutin, Ali Siahkoohi, Gabrio Rizzuti, Bas Peters, Felix J. Herrmann
InvertibleNetworks. jl is a Julia package designed for the scalable implementation of normalizing flows, a method for density estimation and sampling in high-dimensional distributions.
1 code implementation • 12 Apr 2023 • Mathias Louboutin, Ziyi Yin, Rafael Orozco, Thomas J. Grady II, Ali Siahkoohi, Gabrio Rizzuti, Philipp A. Witte, Olav Møyner, Gerard J. Gorman, Felix J. Herrmann
We present the Seismic Laboratory for Imaging and Modeling/Monitoring (SLIM) open-source software framework for computational geophysics and, more generally, inverse problems involving the wave-equation (e. g., seismic and medical ultrasound), regularization with learned priors, and learned neural surrogates for multiphase flow simulations.
no code implementations • 6 Mar 2023 • Rafael Orozco, Mathias Louboutin, Ali Siahkoohi, Gabrio Rizzuti, Tristan van Leeuwen, Felix Herrmann
Our method combines physics-informed methods and data-driven methods to accelerate the reconstruction of the final image.
no code implementations • 3 Jan 2023 • Gabrio Rizzuti, Tim Schakel, Niek R. F. Huttinga, Jan Willem Dankbaar, Tristan van Leeuwen, Alessandro Sbrizzi
Motion artifacts often spoil the radiological interpretation of MR images, and in the most severe cases the scan needs be repeated, with additional costs for the provider.
2 code implementations • 24 Jul 2022 • Ali Siahkoohi, Gabrio Rizzuti, Rafael Orozco, Felix J. Herrmann
While generic and applicable to other inverse problems, by means of a linearized seismic imaging example, we show that our correction step improves the robustness of amortized variational inference with respect to changes in the number of seismic sources, noise variance, and shifts in the prior distribution.
no code implementations • NeurIPS Workshop Deep_Invers 2021 • Rafael Orozco, Ali Siahkoohi, Gabrio Rizzuti, Tristan van Leeuwen, Felix Johan Herrmann
For many ill-posed inverse problems, such as photoacoustic imaging, the uncertainty of the solution is highly affected by measurement noise and data incompleteness (due, for example, to limited aperture).
1 code implementation • 10 Oct 2021 • Ali Siahkoohi, Gabrio Rizzuti, Felix J. Herrmann
We propose to use techniques from Bayesian inference and deep neural networks to translate uncertainty in seismic imaging to uncertainty in tasks performed on the image, such as horizon tracking.
2 code implementations • pproximateinference AABI Symposium 2021 • Ali Siahkoohi, Gabrio Rizzuti, Mathias Louboutin, Philipp A. Witte, Felix J. Herrmann
Obtaining samples from the posterior distribution of inverse problems with expensive forward operators is challenging especially when the unknowns involve the strongly heterogeneous Earth.
no code implementations • 15 Jul 2020 • Ali Siahkoohi, Gabrio Rizzuti, Philipp A. Witte, Felix J. Herrmann
In inverse problems, we often have access to data consisting of paired samples $(x, y)\sim p_{X, Y}(x, y)$ where $y$ are partial observations of a physical system, and $x$ represents the unknowns of the problem.
2 code implementations • 16 Apr 2020 • Gabrio Rizzuti, Ali Siahkoohi, Philipp A. Witte, Felix J. Herrmann
Uncertainty quantification for full-waveform inversion provides a probabilistic characterization of the ill-conditioning of the problem, comprising the sensitivity of the solution with respect to the starting model and data noise.
1 code implementation • 14 Apr 2020 • Ali Siahkoohi, Gabrio Rizzuti, Felix J. Herrmann
The chief advantage of this approach is that the updates for the CNN weights do not involve the modeling operator, and become relatively cheap.
Geophysics Image and Video Processing
1 code implementation • 1 Apr 2020 • Ali Siahkoohi, Gabrio Rizzuti, Felix J. Herrmann
In this paper, we focus on how UQ trickles down to horizon tracking for the determination of stratigraphic models and investigate its sensitivity with respect to the imaging result.
2 code implementations • 13 Jan 2020 • Ali Siahkoohi, Gabrio Rizzuti, Felix J. Herrmann
Uncertainty quantification is essential when dealing with ill-conditioned inverse problems due to the inherent nonuniqueness of the solution.
no code implementations • NeurIPS Workshop Deep_Invers 2019 • Felix J. Herrmann, Ali Siahkoohi, Gabrio Rizzuti
We outline new approaches to incorporate ideas from deep learning into wave-based least-squares imaging.