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相关论文: Recovering Missing Slices of the Discrete Fourier …

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We describe the discrete Fourier transform (DFT) for a cyclic group when $p|N$ by factoring $x^N-1$ over finite fields and constructing the Fourier transform and its inverse using B\'{e}zout's identity for polynomials. For the symmetric…

表示论 · 数学 2024-08-13 Jackson Walters

In coherent X-ray diffraction microscopy the diffraction pattern generated by a sample illuminated with coherent x-rays is recorded, and a computer algorithm recovers the unmeasured phases to synthesize an image. By avoiding the use of a…

The Fourier-Transform ghost imaging of both amplitude-only and pure-phase objects was experimentally observed with classical incoherent light at Fresnel distance by a new lensless scheme. The experimental results are in good agreement with…

量子物理 · 物理学 2015-06-26 Minghui Zhang , Qing Wei , Xia Shen , Yongfeng Liu , Honglin Liu , Jing Cheng , Shensheng Han

Truncated Fourier Transforms (TFTs), first introduced by Van der Hoeven, refer to a family of algorithms that attempt to smooth "jumps" in complexity exhibited by FFT algorithms. We present an in-place TFT whose time complexity, measured in…

符号计算 · 计算机科学 2013-01-30 Andrew Arnold

Expensive computation of the conventional sparse Radon transform limits its use for effective transformation of 3D anisotropic seismic data cubes. We introduce a fast algorithm for azimuthally anisotropic 3D Radon transform with sparsity…

地球物理 · 物理学 2025-05-02 Ahmadreza Mokhtari , Ali Gholami

Image demoir\'eing remains a challenging task due to the complex interplay between texture corruption and color distortions caused by moir\'e patterns. Existing methods, especially those relying on direct image-to-image restoration, often…

计算机视觉与模式识别 · 计算机科学 2025-05-27 Xiaoyang Liu , Bolin Qiu , Jiezhang Cao , Zheng Chen , Yulun Zhang , Xiaokang Yang

A Discrete Fourier Transform Method (DFTM) for discrimination between the signal of neutrons and gamma rays in organic scintillation detectors is presented. The method is based on the transformation of signals into the frequency domain…

仪器与探测器 · 物理学 2016-11-03 M. J. Safari , F. Abbasi Davani , H. Afarideh , S. Jamili , E. Bayat

Fourier reconstruction algorithms significantly outperform conventional back-projection algorithms in terms of computation time. In photoacoustic imaging, these methods require interpolation in the Fourier space domain, which creates…

数值分析 · 数学 2016-11-17 M. Haltmeier , O. Scherzer , G. Zangerl

Complementary to conventional and phase X-ray radiography, dark-field imaging has become central in visualizing diffusive scattering signal due to the spatially-unresolved texture within an object. To date most diffusive-dark-field…

医学物理 · 物理学 2023-03-21 Mario A. Beltran , David M. Paganin , Michelle K. Croughan , Kaye S. Morgan

We present a novel method to provide efficient and highly detailed reconstructions. Inspired by wavelets, we learn a neural field that decompose the signal both spatially and frequency-wise. We follow the recent grid-based paradigm for…

计算机视觉与模式识别 · 计算机科学 2023-08-25 Zhijie Wu , Yuhe Jin , Kwang Moo Yi

This paper concerns a fast, one-step iterative technique of imaging extended perfectly conducting cracks with Dirichlet boundary condition. In order to reconstruct the shape of cracks from scattered field data measured at the boundary, we…

数学物理 · 物理学 2017-04-13 Won-Kwang Park

For a sample set of 1024 values, the FFT is 102.4 times faster than the discrete Fourier transform (DFT). The basis for this remarkable speed advantage is the `bit-reversal' scheme of the Cooley-Tukey algorithm. Eliminating the burden of…

历史与综述 · 数学 2007-05-23 Randall D. Peters

The double Fourier sphere (DFS) method uses a clever trick to transform a function defined on the unit sphere to the torus and subsequently approximate it by a Fourier series, which can be evaluated efficiently via fast Fourier transforms.…

数值分析 · 数学 2023-08-03 Sophie Mildenberger , Michael Quellmalz

Explicit encoding of group actions in deep features makes it possible for convolutional neural networks (CNNs) to handle global deformations of images, which is critical to success in many vision tasks. This paper proposes to decompose the…

计算机视觉与模式识别 · 计算机科学 2018-05-18 Xiuyuan Cheng , Qiang Qiu , Robert Calderbank , Guillermo Sapiro

The discrete Fourier transform (DFT) is of fundamental interest in photonic quantum information, yet the ability to scale it to high dimensions depends heavily on the physical encoding, with practical recipes lacking in emerging platforms…

Solving image and video jigsaw puzzles poses the challenging task of rearranging image fragments or video frames from unordered sequences to restore meaningful images and video sequences. Existing approaches often hinge on discriminative…

计算机视觉与模式识别 · 计算机科学 2024-04-12 Jinyang Liu , Wondmgezahu Teshome , Sandesh Ghimire , Mario Sznaier , Octavia Camps

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 -…

数值分析 · 数学 2017-08-14 Santhosh Karnik , Zhihui Zhu , Michael B. Wakin , Justin Romberg , Mark A. Davenport

In this paper we provide a reconstruction algorithm for piecewise-smooth functions with a-priori known smoothness and number of discontinuities, from their Fourier coefficients, posessing the maximal possible asymptotic rate of convergence…

数值分析 · 数学 2014-03-18 Dmitry Batenkov

Reflectance Transformation Imaging (RTI) is very popular for its ability to visually analyze surfaces by enhancing surface details through interactive relighting, starting from only a few tens of photographs taken with a fixed camera and…

计算机视觉与模式识别 · 计算机科学 2025-10-29 Tinsae G. Dulecha , Leonardo Righetto , Ruggero Pintus , Enrico Gobbetti , Andrea Giachetti

We propose an improvement of the known DFT-based indexing technique for fast retrieval of similar time sequences. We use the last few Fourier coefficients in the distance computation without storing them in the index since every coefficient…

数据库 · 计算机科学 2007-05-23 Davood Rafiei , Alberto Mendelzon
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