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Related papers: LOFAR Sparse Image Reconstruction

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Image restoration aims to recover high-quality images from degraded observations. When the degradation process is known, the recovery problem can be formulated as an inverse problem, and in a Bayesian context, the goal is to sample a clean…

Image and Video Processing · Electrical Eng. & Systems 2025-10-13 Darshan Thaker , Abhishek Goyal , René Vidal

LOFAR is a new and sensitive radio interferometer that can be used for dynamic high-resolution imaging spectroscopy at low radio frequencies from 10 to 90 and 110 to 250 MHz. Here we describe its usage for observations of the Sun and in…

Instrumentation and Methods for Astrophysics · Physics 2016-03-22 Frank Breitling , Gottfried Mann , Christian Vocks , Matthias Steinmetz , Klaus G. Strassmeier

Sparse representation using over-complete dictionaries have shown to produce good quality results in various image processing tasks. Dictionary learning algorithms have made it possible to engineer data adaptive dictionaries which have…

Image and Video Processing · Electrical Eng. & Systems 2019-11-11 Nishant Deepak Keni , Amol Mangirish Singbal , Rizwan Ahmed

Photoacoustic tomography is a hybrid biomedical technology, which combines the advantages of acoustic and optical imaging. However, for the conventional image reconstruction method, the image quality is affected obviously by artifacts under…

Image and Video Processing · Electrical Eng. & Systems 2024-06-26 Bowei Yao , Yi Zeng , Haizhao Dai , Qing Wu , Youshen Xiao , Fei Gao , Yuyao Zhang , Jingyi Yu , Xiran Cai

We present a strategy for the recovery of a sparse solution of a common problem in acoustic engineering, which is the reconstruction of sound source levels and locations applying microphone array measurements. The considered task bears…

Optimization and Control · Mathematics 2016-07-04 Laurent Hoeltgen , Michael Breuß , Gert Herold , Ennes Sarradj

Compressive spectral imaging enables to reconstruct the entire three-dimensional (3D) spectral cube from a few multiplexed images. Here, we develop a novel compressive spectral imaging technique using diffractive lenses. Our technique uses…

Image and Video Processing · Electrical Eng. & Systems 2019-09-24 Oğuzhan Fatih Kar , Figen S. Oktem

The non-line-of-sight imaging technique aims to reconstruct targets from multiply reflected light. For most existing methods, dense points on the relay surface are raster scanned to obtain high-quality reconstructions, which requires a long…

Computer Vision and Pattern Recognition · Computer Science 2022-11-29 Xintong Liu , Jianyu Wang , Leping Xiao , Xing Fu , Lingyun Qiu , Zuoqiang Shi

The LOw Frequency ARray - LOFAR - is a new radio interferometer designed with emphasis on flexible digital hardware instead of mechanical solutions. The array elements, so-called stations, are located in the Netherlands and in neighbouring…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Maciej Serylak , Aris Karastergiou , Chris Williams , Wesley Armour , Michael Giles , the LOFAR Pulsar Working Group

We present a new method of removing PSF artifacts and improving the resolution of multidimensional data sources including imagers and spectrographs. Rather than deconvolution, which is translationally invariant, this method is based on…

We introduce an algorithm for the deconvolution of radio synthesis images that accounts for the non-coplanar-baseline effect, allows multiscale reconstruction onto arbitrarily positioned pixel grids, and allows the antenna elements to have…

Instrumentation and Methods for Astrophysics · Physics 2013-10-09 Stephen J. Hardy

The Segmented Planar Imaging Detector for Electro-Optical Reconnaissance (SPIDER) is an optical interferometric imaging device that aims to offer an alternative to the large space telescope designs of today with reduced size, weight and…

Instrumentation and Methods for Astrophysics · Physics 2024-01-17 Matthijs Mars , Marta M. Betcke , Jason D. McEwen

Lensless microscopy with coherent or partially coherent light sources is a well known imaging technique, commonly referred as digital in-line holographic microscopy. In the established methods, both the spatial and temporal coherence of…

Optics · Physics 2020-11-04 Sanjeev Kumar , Manjunatha Mahadevappa , Pranab Kumar Dutta

Compressed sensing (CS) is a promising approach to reduce the number of measurements in photoacoustic tomography (PAT) while preserving high spatial resolution. This allows to increase the measurement speed and to reduce system costs.…

Hyperspectral image (HSI) restoration aims at recovering clean images from degraded observations and plays a vital role in downstream tasks. Existing model-based methods have limitations in accurately modeling the complex image…

Computer Vision and Pattern Recognition · Computer Science 2024-02-27 Li Pang , Xiangyu Rui , Long Cui , Hongzhong Wang , Deyu Meng , Xiangyong Cao

Robustness of deep learning methods for limited angle tomography is challenged by two major factors: a) due to insufficient training data the network may not generalize well to unseen data; b) deep learning methods are sensitive to noise.…

Image and Video Processing · Electrical Eng. & Systems 2019-08-29 Yixing Huang , Alexander Preuhs , Guenter Lauritsch , Michael Manhart , Xiaolin Huang , Andreas Maier

The success of the compressed sensing paradigm has shown that a substantial reduction in sampling and storage complexity can be achieved in certain linear and non-adaptive estimation problems. It is therefore an advisable strategy for…

Information Theory · Computer Science 2014-08-27 Peter Jung , Philipp Walk

Inverse imaging problems that are ill-posed can be encountered across multiple domains of science and technology, ranging from medical diagnosis to astronomical studies. To reconstruct images from incomplete and distorted data, it is…

Image and Video Processing · Electrical Eng. & Systems 2023-11-30 Cesar F. Caiafa , Ramiro M. Irastorza

It is widely believed that sparse supervision is worse than dense supervision in the field of depth completion, but the underlying reasons for this are rarely discussed. To this end, we revisit the task of radar-camera depth completion and…

Computer Vision and Pattern Recognition · Computer Science 2024-07-19 Huadong Li , Minhao Jing , Jiajun Liang , Haoqiang Fan , Renhe Ji

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

Since the 1970s, much of traditional interferometric imaging has been built around variations of the CLEAN algorithm, in both terminology, methodology, and algorithm development. Recent developments in applying new algorithms from convex…

Instrumentation and Methods for Astrophysics · Physics 2020-09-29 Luke Pratley , Melanie Johnston-Hollitt , Jason D. McEwen