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We present a new technique for monitoring microlensing activity even in highly crowded fields, and use this technique to place limits on low-mass MACHOs in the haloes of M31 and the Galaxy. Unlike present Galactic microlensing surveys, we…

Astrophysics · Physics 2009-09-28 Austin B. Tomaney , Arlin P. S. Crotts

Low-light remote sensing images generally feature high resolution and high spatial complexity, with continuously distributed surface features in space. This continuity in scenes leads to extensive long-range correlations in spatial domains…

Computer Vision and Pattern Recognition · Computer Science 2024-09-09 Zishu Yao , Guodong Fan , Jinfu Fan , Min Gan , C. L. Philip Chen

We present a new method designed for optimal subtraction of two images with different seeing. Using image subtraction appears to be essential for the full analysis of the microlensing survey images, however a perfect subtraction of two…

Astrophysics · Physics 2016-08-30 C. Alard , R. H. Lupton

We present the development of a data-driven, AI-based model of the Point Spread Function (PSF) that achieves higher accuracy than the current state-of-the-art approach, "PSF in the Full Field-of-View'' (PIFF). PIFF is widely used in leading…

Instrumentation and Methods for Astrophysics · Physics 2026-02-18 Dayana Andrea Henao Arbeláez , Pierre-François Léget , Andrés Alejandro Plazas Malagón

Nonuniform Fourier data are routinely collected in applications such as magnetic resonance imaging, synthetic aperture radar, and synthetic imaging in radio astronomy. To acquire a fast reconstruction that does not require an online inverse…

Numerical Analysis · Mathematics 2016-10-05 Anne Gelb , Guohui Song

Existing multi-focus image fusion (MFIF) methods often fail to preserve the uncertain transition region and detect small focus areas within large defocused regions accurately. To address this issue, this study proposes a new…

Computer Vision and Pattern Recognition · Computer Science 2024-02-01 Xilai Li , Xiaosong Li , Haishu Tan , Jinyang Li

Optical microscopy is an essential tool in biology and medicine. Imaging thin, yet non-flat objects in a single shot (without relying on more sophisticated sectioning setups) remains challenging as the shallow depth of field that comes with…

Image and Video Processing · Electrical Eng. & Systems 2020-10-14 Adrian Shajkofci , Michael Liebling

Infrared and visible image fusion aims to utilize the complementary information from two modalities to generate fused images with prominent targets and rich texture details. Most existing algorithms only perform pixel-level or feature-level…

Computer Vision and Pattern Recognition · Computer Science 2024-10-31 Kun Hu , Qingle Zhang , Maoxun Yuan , Yitian Zhang

The current data acquisition rate of astronomical transient surveys and the promise for significantly higher rates during in the next decade necessitate the development of novel approaches to analyze astronomical data sets and promptly…

Instrumentation and Methods for Astrophysics · Physics 2022-01-28 Robert Strausbaugh , Antonino Cucchiara , Michael Dow , Sara Webb , Jielai Zhang , Simon Goode , Jeff Cooke

Higher spatial resolution and larger imaging scene are always the goals pursued by advanced space-borne SAR system.High resolution and wide swath SAR imaging can provide more information about the illuminated scene of interest on one…

Signal Processing · Electrical Eng. & Systems 2024-02-27 Xinhua Mao

We have developed an algorithm for transferring radiation in three-dimensional space. The algorithm computes radiation source and sink terms using the Fast Fourier Transform (FFT) method, based on a formulation in which the integral of any…

Astrophysics · Physics 2009-11-07 Renyue Cen

We discuss in some details a novel algorithm for performing partial-sky spherical harmonic transforms (SHT), building on the Fourier-sphere method of Reinecke et al (2023) handling efficiently high numbers of arbitrary locations on the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-20 Julien Carron , Martin Reinecke

A point spread function (PSF) describes the distribution of light for a pure point source in an astronomical image due to the optics of the instrument. An accurate PSF is key for deconvolution, point source photometry and source removal.…

Instrumentation and Methods for Astrophysics · Physics 2025-07-28 Ava Polzin

In this paper a new fractal image compression algorithm is proposed in which the time of encoding process is considerably reduced. The algorithm exploits a domain pool reduction approach, along with using innovative predefined values for…

Computer Vision and Pattern Recognition · Computer Science 2015-01-20 H. Miar Naimi , M. Salarian

We introduce a novel framework for upsampled Point Spread Function (PSF) modeling using pixel-level Bayesian inference. Accurate PSF characterization is critical for precision measurements in many fields including: weak lensing, astrometry,…

Instrumentation and Methods for Astrophysics · Physics 2025-11-26 Connor Stone , Ronan Legin , Alexandre Adam , Nikolay Malkin , Gabriel Missael Barco , Laurence Perreaul-Levasseur , Yashar Hezaveh

This study introduces a novel unsupervised medical image feature extraction method that employs spatial stratification techniques. An objective function based on weight is proposed to achieve the purpose of fast image recognition. The…

Image and Video Processing · Electrical Eng. & Systems 2024-06-28 Qishi Zhan , Dan Sun , Erdi Gao , Yuhan Ma , Yaxin Liang , Haowei Yang

Non-line-of-Sight (NLOS) imaging systems collect light at a diffuse relay surface and input this measurement into computational algorithms that output a 3D volumetric reconstruction. These algorithms utilize the Fast Fourier Transform (FFT)…

Image and Video Processing · Electrical Eng. & Systems 2025-01-14 Talha Sultan , Alex Bocchieri , Chaoying Gu , Xiaochun Liu , Pavel Polynkin , Andreas Velten

In two-dimensional spectrographs, the optical distortions in the spatial and dispersion directions produce variations in the sub-pixel sampling of the background spectrum. Using knowledge of the camera distortions and the curvature of the…

Astrophysics · Physics 2009-12-08 Daniel D. Kelson

We develop the uniform sparse Fast Fourier Transform (usFFT), an efficient, non-intrusive, adaptive algorithm for the solution of elliptic partial differential equations with random coefficients. The algorithm is an adaption of the sparse…

Numerical Analysis · Mathematics 2022-09-05 Lutz Kämmerer , Daniel Potts , Fabian Taubert

Incoherently illuminated or luminescent objects give rise to a low-contrast speckle-like pattern when observed through a thin diffusive medium, as such a medium effectively convolves their shape with a speckle-like point spread function…