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This paper describes a method for extracting rapidly varying, superimposed amplitude- and frequency-modulated signal components. The method is based upon the continuous wavelet transform (CWT) and uses a new wavelet which is a modification…

Mathematical Physics · Physics 2009-11-07 J. D. Harrop , S. N. Taraskin , S. R. Elliott

The wavelet transform has been used for numerous studies in astrophysics, including signal--noise periodicity and decomposition as well as the signature of differential rotation in stellar light curves. In the present work, we apply the…

Solar and Stellar Astrophysics · Physics 2010-09-28 D. B. de Freitas , I. de C. Leão , B. L. Canto Martins , J. R. De Medeiros

The Easy Path Wavelet Transform is an adaptive transform for bivariate functions (in particular natural images) which has been proposed in [1]. It provides a sparse representation by finding a path in the domain of the function leveraging…

Information Theory · Computer Science 2017-02-16 Renato Budinich

The wavelet analysis technique is a powerful tool and is widely used in broad disciplines of engineering, technology, and sciences. In this work, we present a novel scheme of constructing continuous wavelet functions, in which the wavelet…

Instrumentation and Methods for Astrophysics · Physics 2021-08-06 Yun Wang , Ping He

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

The 21 cm radiation of neutral hydrogen provides crucial information for studying the early universe and its evolution. To advance this research, countries have made significant investments in constructing large low-frequency radio…

Instrumentation and Methods for Astrophysics · Physics 2025-08-04 Ming-wei Qin , Rui Tang , Ying-hui Zhou , Chang-jun Lan , Wen-hao Fu , Huan Wang , Bao-lin Hou , Zamri , Jin-song Ping , Wen-jun Yang , Liang Dong

Wavelets are waveform functions that describe transient and unstable variations, such as noises. In this work, we study the advantages of discrete and continuous wavelet transforms (DWT and CWT) of microlensing data to denoise them and…

Instrumentation and Methods for Astrophysics · Physics 2023-10-06 Sedighe Sajadian , Hossein Fatheddin

The notion of wavelets is defined. It is briefly described {\it what} are wavelets, {\it how} to use them, {\it when} we do need them, {\it why} they are preferred and {\it where} they have been applied. Then one proceeds to the…

High Energy Physics - Phenomenology · Physics 2008-11-26 I. M. Dremin

A nearly optimal explicitly-sparse representation for oscillatory kernels is presented in this work by developing a curvelet based method. Multilevel curvelet-like functions are constructed as the transform of the original nodal basis. Then…

Numerical Analysis · Mathematics 2025-04-29 Yanchuang Cao , Jun Liu , Dawei Chen

A fast algorithm for Antoine and Vandergheynst's (1998) directional continuous spherical wavelet transform (CSWT) is presented. Computational requirements are reduced by a factor of O(\sqrt{N}), when N is the number of pixels on the sphere.…

Astrophysics · Physics 2007-05-23 J. D. McEwen , M. P. Hobson , A. N. Lasenby , D. J. Mortlock

We construct a directional spin wavelet framework on the sphere by generalising the scalar scale-discretised wavelet transform to signals of arbitrary spin. The resulting framework is the only wavelet framework defined natively on the…

Information Theory · Computer Science 2017-06-06 Jason D. McEwen , Boris Leistedt , Martin Büttner , Hiranya V. Peiris , Yves Wiaux

The special affine Fourier transform (SAFT) is a promising tool for analyzing non-stationary signals with more degrees of freedom. However, the SAFT fails in obtaining the local features of non-transient signals due to its global kernel and…

Functional Analysis · Mathematics 2020-06-11 Firdous A. Shah , Azhar Y. Tantary , Aajaz A. Teali

In continuous-time wavelet analysis, most wavelet present some kind of symmetry. Based on the Fourier and Hartley transform kernels, a new wavelet multiresolution analysis is proposed. This approach is based on a pair of orthogonal wavelet…

Classical Analysis and ODEs · Mathematics 2015-02-10 L. R. Soares , H. M. de Oliveira , R. J. Cintra

We have analyzed the highest-quality images to be obtained by Cassini of Saturn's main rings after the Saturn Orbit Insertion (SOI) and before the Ring Grazing Orbits (RGO) and Grand Finale (GF). These images are comparable to those of SOI…

Earth and Planetary Astrophysics · Physics 2018-06-06 Matthew S. Tiscareno , Brent E. Harris

Compressed sensing has empowered quality image reconstruction with fewer data samples than previously though possible. These techniques rely on a sparsifying linear transformation. The Daubechies wavelet transform is a common sparsifying…

Image and Video Processing · Electrical Eng. & Systems 2021-06-17 Nicholas Dwork , Daniel O'Connor , Corey A. Baron , Ethan M. I. Johnson , Adam B. Kerr , John M. Pauly , Peder E. Z. Larson

Recent work introduced a unified framework for steerable and directional wavelets in two and three dimensions that ensures many desirable properties, such as a multi-scale structure, fast transforms, and a flexible angular localization. We…

Numerical Analysis · Computer Science 2018-05-08 Christian Lessig

In recent years it has turned out that shearlets have the potential to retrieve directional information so that they became interesting for many applications. Moreover the continuous shearlet transform has the outstanding property to stem…

Numerical Analysis · Mathematics 2014-07-24 S. Häuser , G. Steidl

A method for the design of Fast Haar wavelet for signal processing and image processing has been proposed. In the proposed work, the analysis bank and synthesis bank of Haar wavelet is modified by using polyphase structure. Finally, the…

Multimedia · Computer Science 2010-02-11 V. Ashok , T. Balakumaran , C. Gowrishankar , I. L. A. Vennila , A. Nirmal kumar

Manually tailored wrinkled graphene sheets hold great promise in fabricating smart solid-state devices. In this paper, we employ an energy method to transform the original third-order partial differential equation (pde), i.e. Eq. (1) into…

Applied Physics · Physics 2021-09-21 Yue Chan , Daoju Cai , Kaisheng Cai , Shern-Long Lee , Rumiao Lin , Yong Ren

We present a method of solving partial differential equations on the $n$-dimensional unit sphere using methods based on the continuous wavelet transform derived from approximate identities. We give an explicit analytical solution to the…

Analysis of PDEs · Mathematics 2025-07-08 Ilona Iglewska-Nowak , Piotr Stefaniak