English
Related papers

Related papers: A fast directional continuous spherical wavelet tr…

200 papers

Shearlet theory has become a central tool in analyzing and representing 2D data with anisotropic features. Shearlet systems are systems of functions generated by one single generator with parabolic scaling, shearing, and translation…

Functional Analysis · Mathematics 2010-11-23 Gitta Kutyniok , Jakob Lemvig , Wang-Q Lim

Cosmological perturbation theory is a powerful tool to predict the statistics of large-scale structure in the weakly non-linear regime, but even at 1-loop order it results in computationally expensive mode-coupling integrals. Here we…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-17 Xiao Fang , Jonathan A. Blazek , Joseph E. McEwen , Christopher M. Hirata

This paper is concerned with density estimation of directional data on the sphere. We introduce a procedure based on thresholding on a new type of spherical wavelets called {\it needlets}. We establish a minimax result and prove its…

Statistics Theory · Mathematics 2010-04-30 P. Baldi , G. Kerkyacharian , D. Marinucci , D. Picard

In this paper, we exploit the theory of convolution of index Whittaker transform for study of continuous and discrete Index Whittaker wavelet transform and discuss some of its basic properties. Certain boundedness, Plancherel as well as…

Functional Analysis · Mathematics 2019-08-19 Ashish Pathak , Abhishek

We demonstrate a fast spin-s spherical harmonic transform algorithm, which is flexible and exact for band-limited functions. In contrast to previous work, where spin transforms are computed independently, our algorithm permits the…

Instrumentation and Methods for Astrophysics · Physics 2010-07-22 K. M. Huffenberger , B. D. Wandelt

The paper presents a versatile library of quasi-analytic complex-valued wavelet packets (WPs) which originate from polynomial splines of arbitrary orders. The real parts of the quasi-analytic WPs are the regular spline-based orthonormal WPs…

Numerical Analysis · Mathematics 2020-08-13 Amir Averbuch , Pekka Neittaanmaki , Valery Zheludev

An algorithm is presented to update the multi-fractal spectrum of a time series in constant time when new data arrives. The discrete wavelet transform (DWT) of the time series is first updated for the new data value. This is done optimally…

Chaotic Dynamics · Physics 2007-05-23 Nicolas Brodu

We use hyperbolic wavelet regression for the fast reconstruction of high-dimensional functions having only low dimensional variable interactions. Compactly supported periodic Chui-Wang wavelets are used for the tensorized hyperbolic wavelet…

Numerical Analysis · Mathematics 2024-05-30 Daniel Potts , Laura Weidensager

{.2in} {\small {\bf Abstract.} Due to the extra degrees of freedom, special affine Fourier transform (SAFT) has achieved a respectable status within a short span and got versatile applicability in the areas of signal processing, image…

Functional Analysis · Mathematics 2021-03-31 Owais Ahmad , Neyaz Ahmad Sheikh

Recently, it has been proven [R. Soc. Open Sci. 1 (2014) 140124] that the continuous wavelet transform with non-admissible kernels (approximate wavelets) allows for an existence of the exact inverse transform. Here we consider the…

Functional Analysis · Mathematics 2015-07-20 Eugene B. Postnikov , Elena A. Lebedeva , Anastasia I. Lavrova

We discuss in some details a novel algorithm for performing partial-sky spherical harmonic transforms (SHT), building on the Fourier-sphere method of Reinecke et al (2023) handling efficiently high numbers of arbitrary locations on the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-20 Julien Carron , Martin Reinecke

We introduce an innovative wavelet-based approach to dynamically adjust the local grid resolution to maintain a uniform specified error tolerance. Extending the work of Dubos and Kevlahan (2013), a wavelet multi-scale approximation is used…

Geophysics · Physics 2015-10-28 Matthias Aechtner , Nicholas Kevlahan , Thomas Dubos

This review paper is intended to give a useful guide for those who want to apply discrete wavelets in their practice. The notion of wavelets and their use in practical computing and various applications are briefly described, but rigorous…

High Energy Physics - Phenomenology · Physics 2025-10-20 I. M. Dremin , O. V. Ivanov , V. A. Nechitailo

Vector spherical harmonics on the unit sphere of $\mathbb{R}^3$ have broad applications in geophysics, quantum mechanics and astrophysics. In the representation of a tangent vector field, one needs to evaluate the expansion and the Fourier…

Numerical Analysis · Mathematics 2021-03-25 Quoc T. Le Gia , Ming Li , Yu Guang Wang

Both of Wavelet and Fast Fourier Transform are strong signal processing tools in the field of Data Analysis. In this paper fast fourier transform (FFT) and Wavelet Transform are employed to observe some important features of Solar image…

Computer Vision and Pattern Recognition · Computer Science 2013-12-11 Sabyasachi Mukhopadhyay , Debadatta Dash , Swapnil Barmase , Prasanta K Panigrahi

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

The wavelet tree (Grossi et al. [SODA, 2003]) and wavelet matrix (Claude et al. [Inf. Syst., 47:15--32, 2015]) are compact indices for texts over an alphabet $[0,\sigma)$ that support rank, select and access queries in $O(\lg \sigma)$ time.…

Data Structures and Algorithms · Computer Science 2017-11-13 Johannes Fischer , Florian Kurpicz , Marvin Löbel

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

An exact solution of the homogeneous wave equation, which was found previously, is treated from the point of view of continuous wavelet analysis (CWA). If time is a fixed parameter, the solution represents a new multidimensional mother…

Mathematical Physics · Physics 2007-05-23 Maria V Perel , Mikhail S Sidorenko

A wavelet scattering network computes a translation invariant image representation, which is stable to deformations and preserves high frequency information for classification. It cascades wavelet transform convolutions with non-linear…

Computer Vision and Pattern Recognition · Computer Science 2012-03-09 Joan Bruna , Stéphane Mallat