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Related papers: Multiscale Optimal Filtering on the Sphere

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In vibration-based condition monitoring, optimal filter design improves fault detection by enhancing weak fault signatures within vibration signals. This process involves optimising a derived objective function from a defined objective. The…

Signal Processing · Electrical Eng. & Systems 2024-05-07 Stephan Schmidt , Daniel N. Wilke , Konstantinos C. Gryllias

In this paper we formulate a weighted version of minimum problem (1.4) on the sphere and we show that, for $K\le L$, if $\set{\phi_k}^K_{k=1}$ consists of the spherical functions with degree less than $N$ we can localize the points…

Classical Analysis and ODEs · Mathematics 2008-08-11 Margit Pap

This paper introduces an adaptive filtering process based on shrinking wavelet coefficients from the corresponding signal wavelet representation. The filtering procedure considers a threshold method determined by an iterative algorithm…

Methodology · Statistics 2023-07-21 F. M. Bayer , A. J. Kozakevicius , R. J. Cintra

For the accurate representation and reconstruction of band-limited signals on the sphere, an optimal-dimensionality sampling scheme has been recently proposed which requires the optimal number of samples equal to the number of degrees of…

Information Theory · Computer Science 2017-09-11 Wajeeha Nafees , Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

We review scale-discretized wavelets on the sphere, which are directional and allow one to probe oriented structure in data defined on the sphere. Furthermore, scale-discretized wavelets allow in practice the exact synthesis of a signal…

Information Theory · Computer Science 2013-12-10 J. D. McEwen , P. Vandergheynst , Y. Wiaux

In this work, we derive a generic overcomplete frame thresholding scheme based on risk minimization. Overcomplete frames being favored for analysis tasks such as classification, regression or anomaly detection, we provide a way to leverage…

Audio and Speech Processing · Electrical Eng. & Systems 2017-12-27 Romain Cosentino , Randall Balestriero , Richard Baraniuk , Ankit Patel

Efficient lossless coding of medical volume data with temporal axis can be achieved by motion compensated wavelet lifting. As side benefit, a scalable bit stream is generated, which allows for displaying the data at different resolution…

Image and Video Processing · Electrical Eng. & Systems 2023-02-03 Daniela Lanz , André Kaup

The bilateral filter is known to be quite effective in denoising images corrupted with small dosages of additive Gaussian noise. The denoising performance of the filter, however, is known to degrade quickly with the increase in noise level.…

Computer Vision and Pattern Recognition · Computer Science 2015-05-26 Kunal N. Chaudhury , Kollipara Rithwik

An efficient despeckling method using a quantum-inspired adaptive threshold function is presented for reducing noise of ultrasound images. In the first step, the ultrasound image is decorrelated by an spectrum equalization procedure due to…

Computer Vision and Pattern Recognition · Computer Science 2018-07-10 Hamid Reza Shahdoosti

We propose a new, efficient multi-scale method to decompose a map (or signal in general) into components maps that contain structures of different sizes. In the widely-used wave transform, artifacts containing negative values arise around…

Instrumentation and Methods for Astrophysics · Physics 2022-04-11 Guang-Xing Li

Sensor fusion is a technique used to combine sensors with different noise characteristics into a super sensor that has superior noise performance. To achieve sensor fusion, complementary filters are used in current gravitational-wave…

Instrumentation and Detectors · Physics 2022-09-07 T. T. L. Tsang , T. G. F. Li , T. Dehaeze , C. Collette

In this paper we show that the knowledge of noise statistics contaminating a signal can be effectively used to choose an optimal Gaussian filter to eliminate noise. Very specifically, we show that the additive white Gaussian noise (AWGN)…

Other Computer Science · Computer Science 2014-06-13 Sunil Kopparapu , M Satish

Despite quantum networking concepts, designs, and hardware becoming increasingly mature, there is no consensus on the optimal wavelength for free-space systems. We present an in-depth analysis of a daytime free-space quantum channel as a…

We derive an optimal linear filter to suppress the noise from the COBE DMR sky maps for a given power spectrum. We then apply the filter to the first-year DMR data, after removing pixels within $20^\circ$ of the Galactic plane from the…

Astrophysics · Physics 2009-10-22 Emory F. Bunn , Karl B. Fisher , Yehuda Hoffman , Ofer Lahav , Joseph Silk , Saleem Zaroubi

The problem of denoising a one-dimensional signal possessing varying degrees of smoothness is ubiquitous in time-domain astronomy and astronomical spectroscopy. For example, in the time domain, an astronomical object may exhibit a smoothly…

Instrumentation and Methods for Astrophysics · Physics 2022-02-01 Collin A. Politsch , Jessi Cisewski-Kehe , Rupert A. C. Croft , Larry Wasserman

It is shown that any convolution operator in the time domain can be represented exactly as a multiplication operator in the time-scale (wavelet) domain. The Mellin transform gives a one-to-one correspondence between frequency filters…

Mathematical Physics · Physics 2007-05-23 Gerald Kaiser

Point-source contamination in high-precision Cosmic Microwave Background (CMB) maps severely affects the precision of cosmological parameter estimates. Among the methods that have been proposed for source detection, wavelet techniques based…

Astrophysics · Physics 2009-11-07 R. Vio , L. Tenorio , W. Wamsteker

In this paper we are concerned with the global minimization of a possibly non-smooth and non-convex objective function constrained on the unit hypersphere by means of a multi-agent derivative-free method. The proposed algorithm falls into…

Optimization and Control · Mathematics 2021-04-02 Massimo Fornasier , Hui Huang , Lorenzo Pareschi , Philippe Sünnen

A simple, yet general, formalism for the optimized linear combination of astrophysical images is constructed and demonstrated. The formalism allows the user to combine multiple undersampled images to provide oversampled output at high…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Barnaby Rowe , Christopher Hirata , Jason Rhodes

We present in this paper new multiscale transforms on the sphere, namely the isotropic undecimated wavelet transform, the pyramidal wavelet transform, the ridgelet transform and the curvelet transform. All of these transforms can be…

Astrophysics · Physics 2016-08-30 Jean-Luc Starck , Yassir Moudden , Pierrick Abrial , Mai Nguyen