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Related papers: Fast W-Projection for Wide-field Imaging

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Deep neural networks face numerous challenges in hyperspectral image classification, including high-dimensional data, sparse ground object distributions, and spectral redundancy, which often lead to classification overfitting and limited…

Computer Vision and Pattern Recognition · Computer Science 2025-04-16 Guandong Li , Mengxia Ye

A wide-field imager in space could make remarkable progress in two very different frontiers of astronomy: dark energy and extra-solar planets. Embedding such an imager on a much larger and more complicated DE mission would be a poor…

Cosmology and Nongalactic Astrophysics · Physics 2009-02-16 Andrew Gould

Wavefront shaping systems aim to image deep into scattering tissue by reshaping incoming and outgoing light to correct aberrations caused by tissue inhomogeneity However, the desired modulation depends on the unknown tissue structure and…

Optics · Physics 2026-01-14 Sagi Monin , Marina Alterman , Anat Levin

Rectifying the orientation of images represents a daily task for every photographer. This task may be complicated even for the human eye, especially when the horizon or other horizontal and vertical lines in the image are missing. In this…

Computer Vision and Pattern Recognition · Computer Science 2021-05-13 Ionut Mironica , Andrei Zugravu

The energy range of hard X-rays is a key waveband to the study of high energy processes in celestial objects, but still remains poorly explored. In contrast to direct imaging methods used in the low energy X-ray and high energy gamma-ray…

Astrophysics · Physics 2007-05-23 T. P. Li

High-throughput biological imaging is often constrained by a trade-off between acquisition speed and image quality. Fast imaging modalities, such as wide-field fluorescence microscopy, enable large-scale data acquisition but suffer from…

Image and Video Processing · Electrical Eng. & Systems 2026-04-20 Dominik Panek , Carina Rząca , Maksymilian Szczypior , Joanna Sorysz , Krzysztof Misztal , Zbigniew Baster , Zenon Rajfur

We present a fast algorithm for generating full sky, high resolution ($\sim 5'$) simulations of the CMB anisotropy pattern. We also discuss the inverse problem, that of evaluating from such a map the full set of $a_{\ell m}$'s and the…

Astrophysics · Physics 2014-10-13 Pio Francesco Muciaccia , Paolo Natoli , Nicola Vittorio

The new generation of radio interferometers is characterized by high sensitivity, wide fields of view and large fractional bandwidth. To synthesize the deepest images enabled by the high dynamic range of these instruments requires us to…

Instrumentation and Methods for Astrophysics · Physics 2018-04-25 C. Tasse , B. Hugo , M. Mirmont , O. Smirnov , M. Atemkeng , L. Bester , M. J. Hardcastle , R. Lakhoo , S. Perkins , T. Shimwell

Bolton and Schlegel presented a promising deconvolution method to extract 1D spectra from a 2D optical fiber spectral CCD image. The method could eliminate the PSF difference between fibers, extract spectra to the photo noise level, as well…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 Guangwei Li , Haotong Zhang , Zhongrui Bai

The x-ray near-field speckle-scanning concept is an approach recently introduced to obtain absorption, phase, and dark-field images of a sample. In this paper, we present ways of recovering from a sample its ultrasmall-angle x-ray…

Optics · Physics 2015-07-24 Sebastien Berujon , Eric Ziegler

Mid-infrared hyperspectral imaging has become an indispensable tool to spatially resolve chemical information in a wide variety of samples. However, acquiring three-dimensional data cubes is typically time-consuming due to the limited speed…

Optics · Physics 2026-05-29 Jianan Fang , Kun Huang , Ruiyang Qin , Yan Liang , E Wu , Ming Yan , Heping Zeng

This paper introduces an efficient design approach for a fast-convolution-based variable-bandwidth (VBW) filter. The proposed approach is based on a hybrid of frequency sampling and optimization (HFSO), that offers significant computational…

Signal Processing · Electrical Eng. & Systems 2025-03-20 Oksana Moryakova , Håkan Johansson

We propose a new ray-tracing algorithm to measure the weak lensing shear and convergence fields directly from N-body simulations. We calculate the deflection of the light rays lensed by the 3-D mass density field or gravitational potential…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Baojiu Li , Lindsay J. King , Gong-Bo Zhao , HongSheng Zhao

The fast algorithms in Fourier optics have invigorated multifunctional device design and advanced imaging technologies. However, the necessity for fast computations has led to limitations in the widely used conventional Fourier methods,…

Applied Physics · Physics 2024-06-25 Zhi Li , Xuhao Luo , Jing Wang , Xin Yuan , Dongdong Teng , Qiang Song , Huigao Duan

The Wide Field Imager (WFI) is one of two instruments for the Advanced Telescope for High-ENergy Astrophysics (Athena). In this paper we summarise three of the many key science objectives for the WFI - the formation and growth of…

Existing fast algorithms for bilateral and nonlocal means filtering mostly work with grayscale images. They cannot easily be extended to high-dimensional data such as color and hyperspectral images, patch-based data, flow-fields, etc. In…

Computer Vision and Pattern Recognition · Computer Science 2018-11-07 Pravin Nair , Kunal. N. Chaudhury

Ground-based astronomical observations at thermal infrared wavelengths face the problem of extracting the weak astronomical signal from the large and rapidly variable background flux. The observing strategy most commonly used, the so-called…

Astrophysics · Physics 2009-10-31 M. Bertero , P. Boccacci , M. Robberto

Simulated images are essential in algorithm development and instrument testing for optical telescopes. During real observations, images obtained by optical telescopes are affected by spatially variable point spread functions (PSFs), a…

Instrumentation and Methods for Astrophysics · Physics 2025-02-17 Zeyu Bai , Peng Jia , Jiameng Lv , Xiang Zhang , Wennan Xiang , Lin Nie

We describe a new data collection scheme for optical diffusion tomography in which plane wave illumination is combined with multiple projections in the slab imaging geometry. Multiple projection measurements are performed by rotating the…

Medical Physics · Physics 2007-05-23 Vadim A. Markel , John C. Schotland

Imaging below the diffraction limit is always a public interest because of the restricted resolution of conventional imaging systems. To beat the limit, evanescent harmonics decaying in space must participate in the imaging process. Here,…

Optics · Physics 2019-10-02 Tie-Jun Huang , Li-Zheng Yin , Ya Shuang , Jiang-Yu Liu , Yunhua Tan , Pu-Kun Liu