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We present a novel framework for discrete multiresolution analysis of graph signals. The main analytical tool is the samplet transform, originally defined in the Euclidean framework as a discrete wavelet-like construction, tailored to the…

Signal Processing · Electrical Eng. & Systems 2025-07-28 Giacomo Elefante , Gianluca Giacchi , Michael Multerer , Jacopo Quizi

This paper presents an efficient implementation of the Wavenet generation process called Fast Wavenet. Compared to a naive implementation that has complexity O(2^L) (L denotes the number of layers in the network), our proposed approach…

Wavelet theory has been well studied in recent decades. Due to their appealing features such as sparse multiscale representation and fast algorithms, wavelets have enjoyed many tremendous successes in the areas of signal/image processing…

Numerical Analysis · Mathematics 2019-09-27 Bin Han , Michelle Michelle , Yau Shu Wong

Recently single image super resolution is very important research area to generate high resolution image from given low resolution image. Algorithms of single image resolution are mainly based on wavelet domain and spatial domain. Filters…

Computer Vision and Pattern Recognition · Computer Science 2013-09-10 Sapan Naik , Nikunj Patel

We develop a sampling scheme on the sphere that permits accurate computation of the spherical harmonic transform and its inverse for signals band-limited at $L$ using only $L^2$ samples. We obtain the optimal number of samples given by the…

Information Theory · Computer Science 2014-07-25 Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

We introduce a fast algorithm for generating long self-affine profiles. The algorithm, which is based on the fast wavelet transform, is faster than the conventional Fourier filtering algorithm. In addition to increased performance for large…

Disordered Systems and Neural Networks · Physics 2010-05-04 Ingve Simonsen , Alex Hansen

Spherical harmonics provide a smooth, orthogonal, and symmetry-adapted basis to expand functions on a sphere, and they are used routinely in physical and theoretical chemistry as well as in different fields of science and technology, from…

Chemical Physics · Physics 2023-05-02 Filippo Bigi , Guillaume Fraux , Nicholas J. Browning , Michele Ceriotti

We present a promising approach to the extremely fast sensing and correction of small wavefront errors in adaptive optics systems. As our algorithm's computational complexity is roughly proportional to the number of actuators, it is…

Instrumentation and Methods for Astrophysics · Physics 2016-11-26 Christoph U. Keller , Visa Korkiakoski , Niek Doelman , Rufus Fraanje , Raluca Andrei , Michel Verhaegen

We provide a new algorithm for the treatment of the deconvolution problem on the sphere which combines the traditional SVD inversion with an appropriate thresholding technique in a well chosen new basis. We establish upper bounds for the…

Statistics Theory · Mathematics 2016-08-14 Gérard Kerkyacharian , Thanh Mai Pham Ngoc , Dominique Picard

Microlocal analysis provides deep insight into singularity structures and is often crucial for solving inverse problems, predominately, in imaging sciences. Of particular importance is the analysis of wavefront sets and the correct…

Image and Video Processing · Electrical Eng. & Systems 2019-07-11 Héctor Andrade-Loarca , Gitta Kutyniok , Ozan Öktem , Philipp Petersen

Single-pixel imaging is an indirect imaging technique which utilizes simplified optical hardware and advanced computational methods. It offers novel solutions for hyper-spectral imaging, polarimetric imaging, three-dimensional imaging,…

Image and Video Processing · Electrical Eng. & Systems 2018-01-12 Krzysztof M. Czajkowski , Anna Pastuszczak , Rafał Kotyński

We derive optimal filters on the sphere in the context of detecting compact objects embedded in a stochastic background process. The matched filter and the scale adaptive filter are derived on the sphere in the most general setting,…

Astrophysics · Physics 2011-10-28 J. D. McEwen , M. P. Hobson , A. N. Lasenby

Most of existing superpixel methods are designed to segment standard planar images as pre-processing for computer vision pipelines. Nevertheless, the increasing number of applications based on wide angle capture devices, mainly generating…

Computer Vision and Pattern Recognition · Computer Science 2021-02-16 Rémi Giraud , Rodrigo Borba Pinheiro , Yannick Berthoumieu

We propose a novel method for constructing wavelet transforms of functions defined on the vertices of an arbitrary finite weighted graph. Our approach is based on defining scaling using the the graph analogue of the Fourier domain, namely…

Functional Analysis · Mathematics 2009-12-22 David K Hammond , Pierre Vandergheynst , Rémi Gribonval

Estimating accurate high-dimensional transformations remains very challenging, especially in a clinical setting. In this paper, we introduce a multiscale parameterization of deformations to enhance registration and atlas estimation in the…

Optimization and Control · Mathematics 2025-01-31 Fleur Gaudfernau , Eléonore Blondiaux , Stéphanie Allassonnière , Erwan Le Pennec

We describe a new method involving wavelet transforms for deriving the wind velocity associated with atmospheric turbulence layers from Generalized SCIDAR measurements. The algorithm analyses the cross-correlation of a series of…

Astrophysics · Physics 2016-08-30 B. Garcia-Lorenzo , J. J. Fuensalida

We develop an exact wavelet transform on the three-dimensional ball (i.e. on the solid sphere), which we name the flaglet transform. For this purpose we first construct an exact transform on the radial half-line using damped Laguerre…

Information Theory · Computer Science 2013-08-15 B. Leistedt , J. D. McEwen

We propose a method of solving partial differential equations on the $n$-dimen\-sional unit sphere with methods based on the continuous wavelet transform derived from approximate identities.

Mathematical Physics · Physics 2021-09-06 {Ilona Iglewska-Nowak , Piotr Stefaniak

This paper constructs a semi-discrete tight frame of tensor needlets associated with a quadrature rule for tangent vector fields on the unit sphere $\mathbb{S}^2$ of $\mathbb{R}^3$ --- tensor needlets. The proposed tight tensor needlets…

Numerical Analysis · Mathematics 2019-08-01 Ming Li , Philip Broadbridge , Andriy Olenko , Yu Guang Wang

Wavefront shaping systems aim to image deep into scattering tissue by reshaping incoming and outgoing light to correct aberrations caused by tissue inhomogeneity However, the desired modulation depends on the unknown tissue structure and…

Optics · Physics 2026-01-14 Sagi Monin , Marina Alterman , Anat Levin