English
Related papers

Related papers: Multiscale Optimal Filtering on the Sphere

200 papers

This paper proposes a new technique based on nonlinear Adaptive Median filter (AMF) for image restoration. Image denoising is a common procedure in digital image processing aiming at the removal of noise, which may corrupt an image during…

Computer Vision and Pattern Recognition · Computer Science 2010-04-28 T. K. Thivakaran , RM. Chandrasekaran

In this paper we introduce a new linear filtering technique, the so-called matrix filters, that maximizes the signal-to-interference ratio of compact sources of unknown intensity embedded in a set of images by taking into account the…

Astrophysics · Physics 2009-11-13 D. Herranz , J. L. Sanz

Noise is inevitably common in digital images, leading to visual image deterioration. Therefore, a suitable filtering method is required to lessen the noise while preserving the image features (edges, corners, etc.). This paper presents the…

Computer Vision and Pattern Recognition · Computer Science 2024-09-20 Vikas Singh

Cosmic microwave background (CMB) radiation data obtained by different experiments contain, besides the desired signal, a superposition of microwave sky contributions. We present a fast and robust method, using a wavelet decomposition on…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-24 R. Fernández-Cobos , P. Vielva , R. B. Barreiro , E. Martínez-González

Large scale multiple-input multiple-output (MIMO) system is considered one of promising technologies for realizing next-generation wireless communication system (5G) to increasing the degrees of freedom in space and enhancing the link…

Information Theory · Computer Science 2014-07-24 Guan Gui , Li Xu

We describe S2LET, a fast and robust implementation of the scale-discretised wavelet transform on the sphere. Wavelets are constructed through a tiling of the harmonic line and can be used to probe spatially localised, scale-depended…

Information Theory · Computer Science 2013-10-29 B. Leistedt , J. D. McEwen , P. Vandergheynst , Y. Wiaux

We describe a new multi-scale deconvolution algorithm that can also be used in multi-frequency mode. The algorithm only affects the minor clean loop. In single-frequency mode, the minor loop of our improved multi-scale algorithm is over an…

Instrumentation and Methods for Astrophysics · Physics 2017-08-02 A. R. Offringa , O. Smirnov

The performance of laser-based active sensing has been severely limited by two types of noise: electrical noise, stemming from elements; optical noise, laser jamming from an eavesdropper and background from environment. Conventional methods…

Wavelet functions allow the sparse and efficient representation of a signal at different scales. Recently the application of wavelets to the denoising of maps of cosmic microwave background (CMB) fluctuations has been proposed. The…

Astrophysics · Physics 2009-11-07 Klaus Maisinger , M. P. Hobson , A. N. Lasenby

The algorithm of modified wavelet analysis is discussed. It is based on the weighted least squares approximation. Contrary to the Gaussian as a weight function, we propose to use a compact weight function. The accuracy estimates using the…

Instrumentation and Methods for Astrophysics · Physics 2020-05-05 Ivan L. Andronov , Violetta P. Kulynska

We consider approximate maximum likelihood parameter estimation in nonlinear state-space models. We discuss both direct optimization of the likelihood and expectation--maximization (EM). For EM, we also give closed-form expressions for the…

Methodology · Statistics 2015-11-03 Juho Kokkala , Arno Solin , Simo Särkkä

In this paper we present a novel geometric filter, a homogeneous moving least squares fitting-based filter (H-MLS filter), for anisotropic mesh filtering. Instead of fitting the noisy data by a moving parametric surface and projecting the…

Numerical Analysis · Mathematics 2019-12-24 Xunnian Yang

We study the impact of sampling theorems on the fidelity of sparse image reconstruction on the sphere. We discuss how a reduction in the number of samples required to represent all information content of a band-limited signal acts to…

Information Theory · Computer Science 2013-04-17 J. D. McEwen , G. Puy , J. -Ph. Thiran , P. Vandergheynst , D. Van De Ville , Y. Wiaux

This paper proposes novel spectrum sensing algorithms for cognitive radio networks. By assuming known transmitter pulse shaping filter, synchronous and asynchronous receiver scenarios have been considered. For each of these scenarios, the…

Optimization and Control · Mathematics 2013-12-31 Tadilo Endeshaw Bogale , Luc Vandendorpe

This paper investigates the low-complex linear minimum mean squared error (LMMSE) channel estimation in an extra-large scale MIMO system with the spherical wave model (SWM). We model the extra-large scale MIMO channels using the SWM in the…

Information Theory · Computer Science 2023-10-24 Xumin Pu , Zhinan Sun , Qianbin Chen , Shi Jin

This note is devoted to an analysis of the so-called peeling algorithm in wavelet denoising. Assuming that the wavelet coefficients of the signal can be modeled by generalized Gaussian random variables, we compute a critical thresholding…

Statistics Theory · Mathematics 2009-11-23 Céline Lacaux , Aurélie Muller , Radu Ranta , Samy Tindel

The estimation of potential fields such as the gravitational or magnetic potential at the surface of a spherical planet from noisy observations taken at an altitude over an incomplete portion of the globe is a classic example of an…

Statistics Theory · Mathematics 2009-11-11 Frederik J Simons , F. A. Dahlen

Achieving weighted throughput maximization (WTM) through power control has been a long standing open problem in interference-limited wireless networks. The complicated coupling between the mutual interferences of links gives rise to a…

Networking and Internet Architecture · Computer Science 2008-06-10 Liping Qian , Ying Jun Zhang , Jianwei Huang

We propose a class of spherical wavelet bases for the analysis of geophysical models and forthe tomographic inversion of global seismic data. Its multiresolution character allows for modeling with an effective spatial resolution that varies…

We present a new approach to calculate the Wiener filter solution of general data sets. It is trivial to implement, flexible, numerically absolutely stable, and guaranteed to converge. Most importantly, it does not require an ingenious…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-09 Franz Elsner , Benjamin D. Wandelt