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Multi-dimensional discrete Fourier transforms (DFT) are typically decomposed into multiple 1D transforms. Hence, parallel implementations of any multi-dimensional DFT focus on parallelizing within or across the 1D DFT. Existing DFT packages…

Mathematical Software · Computer Science 2019-12-24 Doru Thom Popovici , Martin D. Schatz , Franz Franchetti , Tze Meng Low

Transforming two-dimensional (2D) images into three-dimensional (3D) volumes is a well-known yet challenging problem for the computer vision community. In the medical domain, a few previous studies attempted to convert two or more input…

Image and Video Processing · Electrical Eng. & Systems 2024-04-22 Pouria Rouzrokh , Bardia Khosravi , Shahriar Faghani , Kellen L. Mulford , Michael J. Taunton , Bradley J. Erickson , Cody C. Wyles

Low-dose computed tomography (LDCT) reduces radiation exposure but suffers from image artifacts and loss of detail due to quantum and electronic noise, potentially impacting diagnostic accuracy. Transformer combined with diffusion models…

Image and Video Processing · Electrical Eng. & Systems 2025-07-01 Qiqing Liu , Guoquan Wei , Zekun Zhou , Yiyang Wen , Liu Shi , Qiegen Liu

Most recent advances in 3D generative modeling rely on diffusion or flow-matching formulations. We instead explore a fully autoregressive alternative and introduce GaussianGPT, a transformer-based model that directly generates 3D Gaussians…

Computer Vision and Pattern Recognition · Computer Science 2026-03-30 Nicolas von Lützow , Barbara Rössle , Katharina Schmid , Matthias Nießner

A two-dimensional (2D) mathematical model of quadratically distorted (QD) grating is established with the principles of Fraunhofer diffraction and Fourier optics. Discrete sampling and bisection algorithm are applied for finding numerical…

Optics · Physics 2018-03-22 Yuewei Liu , Yan Feng

Computational tomography (CT) provides high-resolution medical imaging, but it can expose patients to high radiation. X-ray scanners have low radiation exposure, but their resolutions are low. This paper proposes a new conditional diffusion…

Image and Video Processing · Electrical Eng. & Systems 2025-01-20 Yun Su Jeong , Hye Bin Yoo , Il Yong Chun

This paper develops a constructive numerical scheme for Fourier-Bessel approximations on disks compatible with convolutions supported on disks. We address accurate finite Fourier-Bessel transforms (FFBT) and inverse finite Fourier-Bessel…

Numerical Analysis · Mathematics 2023-11-08 Arash Ghaani Farashahi , Gregory S. Chirikjian

The Causal Dynamical Triangulation (CDT) approach to quantum gravity is a lattice approximation to the gravitational path integral. Developed by Ambj\o{}rn, Jurkiewicz and Loll, it has yielded some important results, notably the emergence…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Rajesh Kommu

A general method for recovering missing DCT coefficients in DCT-transformed images is presented in this work. We model the DCT coefficients recovery problem as an optimization problem and recover all missing DCT coefficients via linear…

Multimedia · Computer Science 2012-09-11 Shujun Li , Andreas Karrenbauer , Dietmar Saupe , C. -C. Jay Kuo

We propose a novel framework for fast integral operations by uncovering hidden geometries in the row and column structures of the underlying operators. This is accomplished through the \texttt{Questionnaire} algorithm, an iterative…

Numerical Analysis · Mathematics 2026-02-27 Pei-Chun Su , Ronald R. Coifman

Variational autoencoder is a powerful deep generative model with variational inference. The practice of modeling latent variables in the VAE's original formulation as normal distributions with a diagonal covariance matrix limits the…

Machine Learning · Computer Science 2019-03-11 Sarin Chandy , Amin Rasekh

The article presents a computationally effective algorithm for calculating the multiresolution discrete Fourier transform (MrDFT). The algorithm is based on the idea of reducing the computational complexity which was introduced by Wen and…

Data Structures and Algorithms · Computer Science 2015-07-10 Bartosz Andreatto , Aleksandr Cariow

4D Computed Tomography (4DCT) is widely used for many clinical applications such as radiotherapy treatment planning, PET and ventilation imaging. However, common 4DCT methods reconstruct multiple breath cycles into a single, arbitrary…

Computer Vision and Pattern Recognition · Computer Science 2024-07-02 Yuliang Huang , Bjoern Eiben , Kris Thielemans , Jamie R. McClelland

This PhD tutorial is concerned with a description of the two-dimensional generalized Lorenz-Mie theory (2D-GLMT), a well-established numerical method used to compute the interaction of light with arrays of cylindrical scatterers. This…

Optics · Physics 2015-09-24 Denis Gagnon , Louis J. Dubé

Graph Neural Networks usually rely on the assumption that the graph topology is available to the network as well as optimal for the downstream task. Latent graph inference allows models to dynamically learn the intrinsic graph structure of…

Machine Learning · Computer Science 2023-06-28 Haitz Sáez de Ocáriz Borde , Anees Kazi , Federico Barbero , Pietro Liò

Since the evolution of digital computers, the storage of data has always been in terms of discrete bits that can store values of either 1 or 0. Hence, all computer programs (such as MATLAB), convert any input continuous signal into a…

Signal Processing · Electrical Eng. & Systems 2021-05-07 Omkar Deshpande , Kharanshu Solanki , Sree Pujitha Suribhatla , Sanya Zaveri , Luv Ghodasara

The Wiener-Khinchin theorem for the Fourier-Laplace transformation (WKT-FLT) provides a robust method to calculate numerically single-side Fourier transforms of arbitrary autocorrelation functions from molecular simulations. However, the…

Computational Physics · Physics 2020-04-22 Akira Koyama , David A. Nicholson , Marat Andreev , Gregory C. Rutledge , Koji Fukao , Takashi Yamamoto

The efficient multiangle centered discrete fractional Fourier transform (MA-CDFRFT) [1] has proven to be a useful tool for time-frequency analysis; in this paper, we generalize the MA-CDFRFT to general M -periodic transforms, which, among…

Signal Processing · Electrical Eng. & Systems 2026-05-01 Christian Oswald , Franz Pernkopf

3D Gaussian Splatting (3DGS) enables efficient reconstruction and high-fidelity real-time rendering of complex scenes on consumer hardware. However, due to its rasterization-based formulation, 3DGS is constrained to ideal pinhole cameras…

Graphics · Computer Science 2025-03-26 Qi Wu , Janick Martinez Esturo , Ashkan Mirzaei , Nicolas Moenne-Loccoz , Zan Gojcic

High-quality surface normal can help improve geometry estimation in problems faced by autonomous vehicles, such as collision avoidance and occlusion inference. While a considerable volume of literature focuses on densely scanned indoor…

Computer Vision and Pattern Recognition · Computer Science 2025-02-13 Ancheng Lin , Jun Li , Yusheng Xiang , Wei Bian , Mukesh Prasad