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State-of-the-art methods for large-scale driving-scene LiDAR segmentation often project the point clouds to 2D space and then process them via 2D convolution. Although this corporation shows the competitiveness in the point cloud, it…

Computer Vision and Pattern Recognition · Computer Science 2020-11-20 Xinge Zhu , Hui Zhou , Tai Wang , Fangzhou Hong , Yuexin Ma , Wei Li , Hongsheng Li , Dahua Lin

For nonlinear multispectral computed tomography (CT), accurate and fast image reconstruction is challenging when the scanning geometries under different X-ray energy spectra are inconsistent or mismatched. Motivated by this, we propose an…

Numerical Analysis · Mathematics 2025-07-28 Yu Gao , Chong Chen

We present a new method to achieve high-contrast images using segmented and/or on-axis telescopes. Our approach relies on using two sequential Deformable Mirrors to compensate for the large amplitude excursions in the telescope aperture due…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Laurent Pueyo , Colin Norman

We investigate the amount of primordial information that can be reconstructed from spectroscopic galaxy surveys, as well as what sets the noise in reconstruction at low wavenumbers, by studying a simplified universe in which galaxies are…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Matthew McQuinn

This work presents a novel deep-learning-based pipeline for the inverse problem of image deblurring, leveraging augmentation and pre-training with synthetic data. Our results build on our winning submission to the recent Helsinki Deblur…

Computer Vision and Pattern Recognition · Computer Science 2023-08-08 Theophil Trippe , Martin Genzel , Jan Macdonald , Maximilian März

We describe a new map-making code for cosmic microwave background (CMB) observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere (Wandelt & G\'{o}rski 2001). Our code can account…

Astrophysics · Physics 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

Image restoration is the task of recovering a clean image from a degraded version. In most cases, the degradation is spatially varying, and it requires the restoration network to both localize and restore the affected regions. In this…

Image and Video Processing · Electrical Eng. & Systems 2022-01-04 Maitreya Suin , Kuldeep Purohit , A. N. Rajagopalan

Solutions to inverse problems that are ill-conditioned or ill-posed may have significant intrinsic uncertainty. Unfortunately, analysing and quantifying this uncertainty is very challenging, particularly in high-dimensional problems. As a…

Methodology · Statistics 2016-07-12 Marcelo Pereyra

We introduce a fast iterative non-local shrinkage algorithm to recover MRI data from undersampled Fourier measurements. This approach is enabled by the reformulation of current non-local schemes as an alternating algorithm to minimize a…

Computer Vision and Pattern Recognition · Computer Science 2014-05-22 Yasir Q. Moshin , Greg Ongie , Mathews Jacob

For nonconvex and nonsmooth restoration models, the lower bound theory reveals their good edge recovery ability, and related analysis can help to design convergent algorithms. Existing such discussions are focused on isotropic…

Numerical Analysis · Mathematics 2021-05-25 Chunlin Wu , Xuan Lin , Yufei Zhao

In this paper, we propose a novel design of image deblurring in the form of one-shot convolution filtering that can directly convolve with naturally blurred images for restoration. The problem of optical blurring is a common disadvantage to…

Image and Video Processing · Electrical Eng. & Systems 2019-07-22 Mahdi S. Hosseini , Konstantinos N. Plataniotis

Hyperspectral images are data cubes with two spatial dimensions and a third spectral dimension, providing a spectrum for each pixel, and thus allow the mapping of extended sources' physical properties. In this article, we present the…

Instrumentation and Methods for Astrophysics · Physics 2024-06-19 Julia Lascar , Jérôme Bobin , Fabio Acero

A key processing step in ground-based astronomy involves combining multiple noisy and blurry exposures to produce an image of the night sky with an improved signal-to-noise ratio. Typically, this is achieved via image coaddition, and can be…

Instrumentation and Methods for Astrophysics · Physics 2025-09-15 Yashil Sukurdeep , Tamás Budavári , Andrew J. Connolly , Fausto Navarro

Reconstruction of object or scene surfaces has tremendous applications in computer vision, computer graphics, and robotics. In this paper, we study a fundamental problem in this context about recovering a surface mesh from an implicit field…

Computer Vision and Pattern Recognition · Computer Science 2021-06-21 Jiabao Lei , Kui Jia , Yi Ma

We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements,…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-23 Alex Hall , Andy Taylor

Ill-posed inverse problems are fundamental in many domains, ranging from astrophysics to medical imaging. Emerging diffusion models provide a powerful prior for solving these problems. Existing maximum-a-posteriori (MAP) or posterior…

Computer Vision and Pattern Recognition · Computer Science 2026-05-15 Minseo Kim , Axel Levy , Gordon Wetzstein

Advanced Driver Assistance Systems (ADAS) are designed with the main purpose of increasing the safety and comfort of vehicle occupants. Most of current computer vision-based ADAS perform detection and tracking tasks quite successfully under…

Computer Vision and Pattern Recognition · Computer Science 2024-12-06 Jon Gutiérrez-Zaballa , Koldo Basterretxea , Javier Echanobe , M. Victoria Martínez , Inés del Campo

As ground-based all-sky astronomical surveys will gather millions of images in the coming years, a critical requirement emerges for the development of fast deconvolution algorithms capable of efficiently improving the spatial resolution of…

Instrumentation and Methods for Astrophysics · Physics 2024-07-31 Utsav Akhaury , Pascale Jablonka , Jean-Luc Starck , Frédéric Courbin

Ground-based astronomical observations will continue to produce resolution-limited images due to atmospheric seeing. Deconvolution reverses such effects and thus can benefit extracted science in multifaceted ways. We apply the Scaled…

Instrumentation and Methods for Astrophysics · Physics 2025-11-04 Yash Gondhalekar , Richard M. Feder , Matthew J. Graham , Ajit K. Kembhavi , Margarita Safonova , Snehanshu Saha , Ashish A. Mahabal

We investigate the use of estimators of weak lensing power spectra based on a flat-sky implementation of the Pseudo-Cl (PCl) technique, where the masked shear field is transformed without regard for masked regions of sky. This masking mixes…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-11 Marika Asgari , Andy Taylor , Benjamin Joachimi , Thomas D. Kitching