English
Related papers

Related papers: DCT Approximations Based on Chen's Factorization

200 papers

As an extension of the 2D fractional Fourier transform (FRFT) and a special case of the 2D linear canonical transform (LCT), the gyrator transform was introduced to produce rotations in twisted space/spatial-frequency planes. It is a useful…

Computer Vision and Pattern Recognition · Computer Science 2017-07-13 Soo-Chang Pei , Shih-Gu Huang , Jian-Jiun Ding

Fourier ptychography is a recently explored imaging method for overcoming the diffraction limit of conventional cameras with applications in microscopy and yielding high-resolution images. In order to splice together low-resolution images…

Image and Video Processing · Electrical Eng. & Systems 2020-03-18 Yican Chen , Zhi Luo , Xia Wu , Huidong Yang , Bo Huang

This paper proposes to use Fast Fourier Transformation-based U-Net (a refined fully convolutional networks) and perform image convolution in neural networks. Leveraging the Fast Fourier Transformation, it reduces the image convolution costs…

Computer Vision and Pattern Recognition · Computer Science 2020-10-12 Varsha Nair , Moitrayee Chatterjee , Neda Tavakoli , Akbar Siami Namin , Craig Snoeyink

Low-rank approximation in data streams is a fundamental and significant task in computing science, machine learning and statistics. Multiple streaming algorithms have emerged over years and most of them are inspired by randomized…

Data Structures and Algorithms · Computer Science 2022-09-30 Cuiyu Liu , Chuanfu Xiao , Mingshuo Ding , Chao Yang

Discrete trigonometric transforms (DTTs), such as the DCT-2 and the DST-7, are widely used in video codecs for their balance between coding performance and computational efficiency. In contrast, data-dependent transforms, such as the…

Image and Video Processing · Electrical Eng. & Systems 2025-11-25 Samuel Fernández-Menduiña , Eduardo Pavez , Antonio Ortega , Tsung-Wei Huang , Thuong Nguyen Canh , Guan-Ming Su , Peng Yin

Recently, a fast alternating minimization algorithm for total variation image deblurring (FTVd) has been presented by Wang, Yang, Yin, and Zhang [{\em SIAM J. Imaging Sci.}, 1 (2008), pp. 248--272]. The method in a nutshell consists of a…

Functional Analysis · Mathematics 2013-09-02 Zheng-Jian Bai , Daniele Cassani , Marco Donatelli , Stefano Serra-Capizzano

Holographic MIMO (hMIMO) systems with a massive number of individually controlled antennas N make minimum mean square error (MMSE) channel estimation particularly challenging, due to its computational complexity that scales as $N^3$ . This…

Information Theory · Computer Science 2023-12-19 Antonio Alberto D'Amico , Giacomo Bacci , Luca Sanguinetti

We present an efficient computational approach to perform real-space electronic structure calculations using an adaptive higher-order finite-element discretization of Kohn-Sham density-functional theory (DFT). To this end, we develop an…

Computational Physics · Physics 2015-06-05 Phani Motamarri , Michael R Nowak , Kenneth Leiter , Jaroslaw Knap , Vikram Gavini

Image reconstruction in Multispectral Computed Tomography (MSCT) requires solving a challenging nonlinear inverse problem, commonly tackled via iterative optimization algorithms. Existing methods necessitate computing the derivative of the…

Numerical Analysis · Mathematics 2024-02-20 Thomas Prohaszka , Lukas Neumann , Markus Haltmeier

We present a new algorithm for 3D cone-beam tomography. The algorithm is based on decomposition of the cone-beam backprojection operation and angular decimation. It has computational complexity of $O(N^{3.5})$ and allows considerable…

Medical Physics · Physics 2017-08-28 Vladyslav Andriiashen , Danila Kozhevnikov

We introduce a Fourier-based fast algorithm for Gaussian process regression in low dimensions. It approximates a translationally-invariant covariance kernel by complex exponentials on an equispaced Cartesian frequency grid of $M$ nodes.…

Computation · Statistics 2023-05-19 Philip Greengard , Manas Rachh , Alex Barnett

Compared with conventional single-energy computed tomography (CT), dual-energy CT (DECT) provides better material differentiation but most DECT imaging systems require dual full-angle projection data at different X-ray spectra. Relaxing the…

Recent works have successfully applied some types of Convolutional Neural Networks (CNNs) to reduce the noticeable distortion resulting from the lossy JPEG/MPEG compression technique. Most of them are built upon the processing made on the…

Image and Video Processing · Electrical Eng. & Systems 2025-10-14 Antonio J G Busson , Paulo R C Mendes , Daniel de S Moraes , Álvaro M da Veiga , Álan L V Guedes , Sérgio Colcher

Computed Tomography (CT) is an essential non-destructive three dimensional imaging modality used in medicine, security screening, and inspection of manufactured components. Typical CT data acquisition entails the collection of a thousand or…

Medical Physics · Physics 2024-10-11 Kyle M. Champley , Michael B. Zellner , Joseph W. Tringe , Harry E. Martz

A joint image reconstruction and segmentation approach based on disentangled representation learning was trained to enable cardiac cine MR imaging in real-time and under free-breathing. An exploratory feasibility study tested the proposed…

We present the Fast Chebyshev Transform (FCT), a fast, randomized algorithm to compute a Chebyshev approximation of functions in high-dimensions from the knowledge of the location of its nonzero Chebyshev coefficients. Rather than sampling…

Numerical Analysis · Mathematics 2023-10-03 Dalton Jones , Pierre-David Letourneau , Matthew J. Morse , M. Harper Langston

This paper proposes a fast and unsupervised scheme for the polygonal approximation of a closed digital curve. It is demonstrated that the approximation scheme is faster than state-of-the-art approximation and is competitive with Rosin's…

Graphics · Computer Science 2025-08-13 Bimal Kumar Ray

Cyclotomic fast Fourier transforms (CFFTs) are efficient implementations of discrete Fourier transforms over finite fields, which have widespread applications in cryptography and error control codes. They are of great interest because of…

Information Theory · Computer Science 2011-08-23 Xuebin Wu , Zhiyuan Yan

High radiation dose in computed tomography (CT) scans increases the lifetime risk of cancer, which become a major clinical concern. The backprojection-filtration (BPF) algorithm could reduce radiation dose by reconstructing images from…

Medical Physics · Physics 2013-11-20 Yan Bin , Deng Lin , Han Yu , Zhang Feng , Wang Xian Chao , Li Lei

The discrete prolate spheroidal sequences (DPSS's) provide an efficient representation for discrete signals that are perfectly timelimited and nearly bandlimited. Due to the high computational complexity of projecting onto the DPSS basis -…

Numerical Analysis · Mathematics 2017-08-14 Santhosh Karnik , Zhihui Zhu , Michael B. Wakin , Justin Romberg , Mark A. Davenport