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We present a joint SO(3)-spectral domain filtering framework using directional spatially localized spherical harmonic transform (DSLSHT), for the estimation and enhancement of random anisotropic signals on the sphere contaminated by random…

Signal Processing · Electrical Eng. & Systems 2021-02-03 Adeem Aslam , Zubair Khalid

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

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

In this paper, we investigate in detail the structures of the variational characterization $A_{N,t}$ of the spherical $t$-design, its gradient $\nabla A_{N,t}$, and its Hessian $\mathcal{H}(A_{N,t})$ in terms of fast spherical harmonic…

Numerical Analysis · Mathematics 2023-12-06 Yuchen Xiao , Xiaosheng Zhuang

Multi-channel speech enhancement extracts speech using multiple microphones that capture spatial cues. Effectively utilizing directional information is key for multi-channel enhancement. Deep learning shows great potential on multi-channel…

Sound · Computer Science 2023-09-21 Jiahui Pan , Pengjie Shen , Hui Zhang , Xueliang Zhang

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

Acoustic signal processing in the spherical harmonics domain (SHD) is an active research area that exploits the signals acquired by higher order microphone arrays. A very important task is that concerning the localization of active sound…

Audio and Speech Processing · Electrical Eng. & Systems 2024-01-29 Maximo Cobos , Mirco Pezzoli , Fabio Antonacci , Augusto Sarti

We present the 2-point function from Fast and Accurate Spherical Bessel Transformation (2-FAST) algorithm for a fast and accurate computation of integrals involving one or two spherical Bessel functions. These types of integrals occur when…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-17 Henry S. Grasshorn Gebhardt , Donghui Jeong

We develop a method to estimate the power spectrum of a stochastic process on the sphere from data of limited geographical coverage. Our approach can be interpreted either as estimating the global power spectrum of a stationary process when…

Instrumentation and Methods for Astrophysics · Physics 2013-06-17 Mark A. Wieczorek , Frederik J. Simons

Utilizing spherical harmonic (SH) domain has been established as the default method of obtaining continuity over space in head-related transfer functions (HRTFs). This paper concerns different variants of extending this solution by…

Audio and Speech Processing · Electrical Eng. & Systems 2023-07-19 Adam Szwajcowski

A fast and exact algorithm is developed for the spin +-2 spherical harmonics transforms on equi-angular pixelizations on the sphere. It is based on the Driscoll and Healy fast scalar spherical harmonics transform. The theoretical exactness…

Astrophysics · Physics 2008-11-26 Y. Wiaux , L. Jacques , P. Vandergheynst

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

In this article, we present a space-frequency theory for spherical harmonics based on the spectral decomposition of a particular space-frequency operator. The presented theory is closely linked to the theory of ultraspherical polynomials on…

Numerical Analysis · Mathematics 2013-07-16 Wolfgang Erb , Sonja Mathias

We give some new results related to the directional short-time Fourier transform (DSTFT) and extend them on the spaces $\mathcal K_{1}(\mathbb R^{n})$ and $\mathcal K_{1}({\mathbb R})\widehat{\otimes}\mathcal U(\mathbb C^n)$ and their…

Functional Analysis · Mathematics 2017-08-28 Sanja Atanasova , Stevan Pilipovic , Katerina Saneva

We study the real-time dynamics retrieval from a time series via the time-frequency (TF) analysis with the minimal latency guarantee. While different from the well-known intrinsic latency definition in the filter design, a rigorous…

Multimedia · Computer Science 2016-06-30 Li Su , Hau-tieng Wu

The objective of polarization rendering is to simulate the interaction of light with materials exhibiting polarization-dependent behavior. However, integrating polarization into rendering is challenging and increases computational costs…

Graphics · Computer Science 2025-01-15 Shinyoung Yi , Donggun Kim , Jiwoong Na , Xin Tong , Min H. Kim

Accurately estimating the point spread function (PSF) of an optical system requires solving free-space wave propagation, which entails evaluating a diffraction integral. This integral is traditionally computed numerically using Fast Fourier…

Image and Video Processing · Electrical Eng. & Systems 2026-05-22 Nicholas Ganino , Qi Guo

We revisit the spherical Radon transform, also called the Funk-Radon transform, viewing it as an axisymmetric convolution on the sphere. Viewing the spherical Radon transform in this manner leads to a straightforward derivation of its…

Information Theory · Computer Science 2020-07-07 Jason D. McEwen , Matthew A. Price

The boundary integral method is an efficient approach for solving time-harmonic acoustic obstacle scattering problems. The main computational task is the evaluation of an oscillatory boundary integral at each discretization point of the…

Numerical Analysis · Mathematics 2014-09-17 Lexing Ying

In the last decade diffusion MRI has become a powerful tool to non-invasively study white-matter integrity in the brain. Recently many research groups have focused their attention on multi-shell spherical acquisitions with the aim of…

Quantitative Methods · Quantitative Biology 2011-06-02 A. Daducci , J. D. McEwen , D. Van De Ville , J. -Ph. Thiran , Y. Wiaux