English
Related papers

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

200 papers

The Wide Field X-Ray Telescope (WFXT) is a medium-class mission designed to be 2-orders-of-magnitude more sensitive than any previous or planned X-ray mission for large area surveys and to match in sensitivity the next generation of…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-01 P. Rosati , S. Borgani , R. Gilli , M. Paolillo , P. Tozzi , S. Murray , R. Giacconi , A. Ptak , M. Weisskopf , W. Forman , C. Jones , the WFXT Team

We present a method for speckle holography that is optimised for crowded fields. Its two key features are an iterativ improvement of the instantaneous Point Spread Functions (PSFs) extracted from each speckle frame and the (optional)…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 R. Schoedel , S. Yelda , A. Ghez , J. H. V. Girard , L. Labadie , R. Rebolo , A. Perez-Garrido , M. R. Morris

Ghost imaging needs massive measurements to obtain an image with good visibility and the imaging speed is usually very low. In order to realize real-time high-resolution ghost imaging of a target which is located in a scenario with a large…

Image and Video Processing · Electrical Eng. & Systems 2019-05-22 Cheng Zhou , Tian Tian , Chao Gao , Wenli Gong , Lijun Song

This contribution deals with image restoration in optical systems with coherent illumination, which is an important topic in astronomy, coherent microscopy and radar imaging. Such optical systems suffer from wavefront distortions, which are…

Instrumentation and Methods for Astrophysics · Physics 2017-04-04 Claudius Zelenka , Reinhard Koch

In this paper, we present a numerical algorithm for the accurate and efficient computation of the convolution of the frequency domain layered media Green's function with a given density function. Instead of compressing the convolution…

Numerical Analysis · Mathematics 2020-06-16 Min Hyung Cho , Jingfang Huang

In this paper, we describe the principle of a multi-aperture interferometer that uses a phase-shifting technique and is suitable for quick, snapshot imaging of astrophysical objects at extreme angular resolution through Fourier inversion. A…

Optics · Physics 2015-05-28 Francois Henault

The study of astronomical phenomena through ground-based observations is always challenged by the distorting effects of Earth's atmosphere. Traditional methods of post-facto image correction, essential for correcting these distortions,…

Instrumentation and Methods for Astrophysics · Physics 2024-08-14 A. Asensio Ramos

We present an efficient spin-photon interface for free-space vertical emission coupling. Using a \rev{dipole model}, we show that our design achieves a far-field collection efficiency of 96\% at the numerical aperture of 0.7 with a 95\%…

Quantum Physics · Physics 2026-03-25 Siavash Mirzaei-Ghormish , Jeddy Bennett , Ryan M. Camacho

Recently, the use of circle representation has emerged as a method to improve the identification of spherical objects (such as glomeruli, cells, and nuclei) in medical imaging studies. In traditional bounding box-based object detection,…

Computer Vision and Pattern Recognition · Computer Science 2024-12-02 Jialin Yue , Tianyuan Yao , Ruining Deng , Quan Liu , Juming Xiong , Junlin Guo , Haichun Yang , Yuankai Huo

Face super-resolution aims to reconstruct a high-resolution face image from a low-resolution face image. Previous methods typically employ an encoder-decoder structure to extract facial structural features, where the direct downsampling…

Computer Vision and Pattern Recognition · Computer Science 2024-07-31 Wenjie Li , Heng Guo , Xuannan Liu , Kongming Liang , Jiani Hu , Zhanyu Ma , Jun Guo

Indirect image registration is a promising technique to improve image reconstruction quality by providing a shape prior for the reconstruction task. In this paper, we propose a novel hybrid method that seeks to reconstruct high quality…

Image and Video Processing · Electrical Eng. & Systems 2019-12-18 Jiulong Liu , Angelica I. Aviles-Rivero , Hui Ji , Carola-Bibiane Schönlieb

We introduce the concept of compressed convolution, a technique to convolve a given data set with a large number of non-orthogonal kernels. In typical applications our technique drastically reduces the effective number of computations. The…

Instrumentation and Methods for Astrophysics · Physics 2014-01-08 F. Elsner , B. D. Wandelt

Wireless channel modeling in complex environments is crucial for wireless communication system design and deployment. Traditional channel modeling approaches face challenges in balancing accuracy, efficiency, and scalability, while recent…

Signal Processing · Electrical Eng. & Systems 2025-12-15 Zihang Zeng , Shu Sun , Meixia Tao , Yin Xu , Xianghao Yu

Image subtraction is essential for transient detection in time-domain astronomy. The point spread function (PSF), photometric scaling, and sky background generally vary with time and across the field-of-view for imaging data taken with…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 Lei Hu , Lifan Wang , Xingzhuo Chen , Jiawen Yang

We suggest a two-dimensional wavelet devised to deduce the large-scale structure of a physical field (e.g., the Galactic magnetic field) from its integrals along straight paths from irregularly spaced data points to a fixed interior point…

Astrophysics · Physics 2009-11-07 R. Stepanov , P. Frick , A. Shukurov , D. Sokoloff

We present several diverse applications of the spherical fast convolution method suggested by Wandelt and Gorski (2001), which is useful for studies of telescope optical properties and for construction of shaped filters for analysis of…

Astrophysics · Physics 2007-09-18 K. M. Huffenberger , I. J. O'Dwyer , K. M. Gorski , B. D. Wandelt

Running time of the light field depth estimation algorithms is typically high. This assessment is based on the computational complexity of existing methods and the large amounts of data involved. The aim of our work is to develop a simple…

Computer Vision and Pattern Recognition · Computer Science 2019-08-01 Yuriy Anisimov , Oliver Wasenmüller , Didier Stricker

Two subspace fitting approaches are proposed for wideband near-field localization. Unlike in conventional far-field systems, where distance and angle can be estimated separately, spherical wave propagation in near-field systems couples…

Signal Processing · Electrical Eng. & Systems 2025-08-07 Ruiyun Zhang , Zhaolin Wang , Zhiqing Wei , Yuanwei Liu , Zehui Xiong , Zhiyong Feng

We present a blind multiframe image-deconvolution method based on robust statistics. The usual shortcomings of iterative optimization of the likelihood function are alleviated by minimizing the M-scale of the residuals, which achieves more…

Instrumentation and Methods for Astrophysics · Physics 2017-11-09 Matthias Lee , Tamas Budavari , Richard White , Charles Gulian

The Wide-Field InfraRed Space Telescope (WFIRST) will be capable of delivering precise astrometry for faint sources over the enormous field of view of its main camera, the Wide-Field Imager (WFI). This unprecedented combination will be…

‹ Prev 1 8 9 10 Next ›