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The Shack-Hartmann Wavefront Sensor (WFS) is well-known in the fields of optical metrology, wavefront sensing in astronomy, and ophthalmologic control applications. The purpose of this communication is to bring new insights on the…

Instrumentation and Methods for Astrophysics · Physics 2019-09-12 Francois Henault , Cyril Pannetier

Image pre-processing in the frequency domain has traditionally played a vital role in computer vision and was even part of the standard pipeline in the early days of deep learning. However, with the advent of large datasets, many…

Computer Vision and Pattern Recognition · Computer Science 2020-11-24 Cristina Vasconcelos , Hugo Larochelle , Vincent Dumoulin , Nicolas Le Roux , Ross Goroshin

In this letter, a fast Fourier transform (FFT)-enhanced low-complexity super-resolution sensing algorithm for near-field source localization with both angle and range estimation is proposed. Most traditional near-field source localization…

Signal Processing · Electrical Eng. & Systems 2024-11-26 Yuxiao Wu , Huizhi Wang , Yong Zeng

Currently, many face forgery detection methods aggregate spatial and frequency features to enhance the generalization ability and gain promising performance under the cross-dataset scenario. However, these methods only leverage one level…

Computer Vision and Pattern Recognition · Computer Science 2022-10-11 Jie Liu , Jingjing Wang , Peng Zhang , Chunmao Wang , Di Xie , Shiliang Pu

The Fractional Fourier Transform (FRFT) has been playing a unique and increasingly important role in signal and image processing. In this letter, we investigate the property of frequency shift in two-dimensional FRFT (2D-FRFT) domain. It is…

Signal Processing · Electrical Eng. & Systems 2021-03-02 Lei Gao , Lin Qi , Ling Guan

Light-pulse atom interferometers serve as tools for high-precision metrology and are targeting measurements of relativistic effects. This development is facilitated by extended interrogation times and large-momentum-transfer techniques…

Quantum Physics · Physics 2025-05-06 Christian Niehof , Daniel Derr , Enno Giese

In principle, diffractive optics, particularly Phase Fresnel Lenses (PFLs), offer the ability to construct large, diffraction-limited, and highly efficient X-ray/$\gamma$-ray telescopes, leading to dramatic improvement in angular resolution…

We study an inverse acoustic scattering problem by the Factorization Method when the unknown scatterer consists of two objects with different physical properties. Especially, we consider the following two cases: One is the case when each…

Analysis of PDEs · Mathematics 2021-06-16 Takashsi Furuya

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

Treatments of Fraunhofer diffraction normally approximate the inclination factor in the diffraction integral by 1, but this is not necessary. In this paper, the Rayleigh-Sommerfeld diffraction integral is used and a complete description of…

Physics Education · Physics 2007-05-23 Robert L. Lucke

In this paper, we consider a method for fast numerical computation of the Fourier transform of a slowly decaying function with given accuracy in given ranges of the frequency. In these decades, some useful formulas for the Fourier transform…

Numerical Analysis · Mathematics 2015-07-28 Ken'ichiro Tanaka

The paper presents an alternative way to classical stereocorrelation. First, 2D image processing of random patterns is described. Sub-pixel displacements are determined using phase analysis. Then distortion evaluation is presented. The…

Classical Physics · Physics 2013-11-18 Jérôme Molimard , Gaetan Boyer , Hassan Zahouani

We consider an inverse source problem for partially coherent light propagating in the Fresnel regime. The data is the coherence of the field measured away from the source. The reconstruction is based on a minimum residue formulation, which…

Fast Fourier Transform (FFT) is an efficient algorithm to compute the Discrete Fourier Transform (DFT) and its inverse. In this paper, we pay special attention to the description of complex-data FFT. We analyze two common descriptions of…

Numerical Analysis · Computer Science 2011-10-28 Zhengjun Cao , Xiao Fan

Image identification is one of the most challenging tasks in different areas of computer vision. Scale-invariant feature transform is an algorithm to detect and describe local features in images to further use them as an image matching…

Computer Vision and Pattern Recognition · Computer Science 2018-03-15 Ebrahim Karami , Mohamed Shehata , Andrew Smith

This paper presents a new FDTD-based optical simulation model dedicated to describe the optical performances of CMOS image sensors taking into account diffraction effects. Following market trend and industrialization constraints, CMOS image…

Optics · Physics 2023-10-17 Flavien Hirigoyen , Axel Crocherie , Jérôme Vaillant , Yvon Cazaux

This paper demonstrates a method of interpreting the mechanism of aberration of optical systems based on non-Fourier transform optical transfer function (OTF). According to the parameters of object plane cosine fringe, we obtain the…

Optics · Physics 2018-12-27 Yu Bai , Jiaqi Chen , Fangjie Li , Zhenming Zhao

Aliasing artifacts in renderings produced by Neural Radiance Field (NeRF) is a long-standing but complex issue in the field of 3D implicit representation, which arises from a multitude of intricate causes and was mitigated by designing more…

Computer Vision and Pattern Recognition · Computer Science 2024-07-11 Ganlin Yang , Kaidong Zhang , Jingjing Fu , Dong Liu

Pseudo-spectral method is one of the most accurate techniques for simulating turbulent flows. Fast Fourier transform (FFT) is an integral part of this method. In this paper, we present a new procedure to compute FFT in which we save…

Mathematical Software · Computer Science 2014-06-24 A. G. Chatterjee , M. K. Verma , M. Chaudhuri

Fresnel lenses offer the possibility of concentrating the flux of X-rays or gamma-rays flux falling on a geometric area of many square metres onto a focal point which need only be a millimetre or so in diameter (and which may even be very…

Astrophysics · Physics 2008-11-26 G. K. Skinner
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