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Image fusion produces a single fused image from a set of input images. A new method for image fusion is proposed based on Weighted Average Merging Method (WAMM) in the NonSubsampled Contourlet Transform (NSCT) domain. A performance analysis…

Computer Vision and Pattern Recognition · Computer Science 2012-05-09 Manu V T , Philomina Simon

Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D Spherical Fourier-Bessel (SFB) analysis in spherical coordinates is natural. Wavelets are particularly well-suited to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 F. Lanusse , A. Rassat , J. -L. Starck

No existing spherical convolutional neural network (CNN) framework is both computationally scalable and rotationally equivariant. Continuous approaches capture rotational equivariance but are often prohibitively computationally demanding.…

Computer Vision and Pattern Recognition · Computer Science 2023-01-31 Jeremy Ocampo , Matthew A. Price , Jason D. McEwen

We present the first application of the Wavelet Scattering Transform (WST) in order to constrain the nature of gravity using the three-dimensional (3D) large-scale structure of the universe. Utilizing the Quijote-MG N-body simulations, we…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-12 Georgios Valogiannis , Francisco Villaescusa-Navarro , Marco Baldi

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 study the spherical Mexican hat wavelet (SMHW) as a detector of primordial non-Gaussianity of the local type on the Cosmic Microwave Background (CMB) anisotropies. For this purpose we define third order statistics based on the wavelet…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 A. Curto , E. Martinez-Gonzalez , R. B. Barreiro

The success of convolutional networks in learning problems involving planar signals such as images is due to their ability to exploit the translation symmetry of the data distribution through weight sharing. Many areas of science and…

Machine Learning · Computer Science 2019-04-23 Taco Cohen , Mario Geiger , Jonas Köhler , Max Welling

Wavelet based algorithms in numerical analysis are similar to other transform methods in that vectors and operators are expanded into a basis and the computations take place in this new system of coordinates. However, due to the recursive…

comp-gas · Physics 2008-02-03 G. Beylkin

We present a new approach to numerically model continuum radiative transfer based on the Optically Thin Variable Eddington Tensor (OTVET) approximation. Our method insures the exact conservation of the photon number and flux (in the…

Astrophysics · Physics 2009-11-06 Nickolay Y. Gnedin , Tom Abel

Texture classification is an important and challenging problem in many image processing applications. While convolutional neural networks (CNNs) achieved significant successes for image classification, texture classification remains a…

Computer Vision and Pattern Recognition · Computer Science 2017-07-25 Shin Fujieda , Kohei Takayama , Toshiya Hachisuka

It is known that the continuous wavelet transform of a function $f$ decays very rapidly near the points where $f$ is smooth, while it decays slowly near the irregular points. This property allows one to precisely identify the singular…

Functional Analysis · Mathematics 2007-05-23 Gitta Kutyniok , Demetrio Labate

In this article, we present an $O(N \log N)$ rapidly convergent algorithm for the numerical approximation of the convolution integral with radially symmetric weakly singular kernels and compactly supported densities. To achieve the reduced…

Numerical Analysis · Mathematics 2021-07-09 Awanish Kumar Tiwari , Ambuj Pandey , Jagabandhu Paul , Akash Anand

In this article, we construct discrete tight frames for $L^2(\mathbb{S}^{d-1})$, $d\geq3$, which consist of localized polynomial wavelets with adjustable degrees of directionality. In contrast to the well studied isotropic case, these…

Classical Analysis and ODEs · Mathematics 2025-12-09 Frederic Schoppert

Many areas of science and engineering encounter data defined on spherical manifolds. Modelling and analysis of spherical data often necessitates spherical harmonic transforms, at high degrees, and increasingly requires efficient computation…

Computational Physics · Physics 2025-06-19 Matthew A. Price , Jason D. McEwen

Volumetric maps are widely used in robotics due to their desirable properties in applications such as path planning, exploration, and manipulation. Constant advances in mapping technologies are needed to keep up with the improvements in…

Robotics · Computer Science 2023-06-05 Victor Reijgwart , Cesar Cadena , Roland Siegwart , Lionel Ott

We propose an image-based flow decomposition developed from the two-dimensional (2D) tensor empirical wavelet transform (EWT) (Gilles 2013). The idea is to decompose the instantaneous flow data, or its visualisation, adaptively according to…

Fluid Dynamics · Physics 2020-12-24 Jie Ren , Xuerui Mao , Song Fu

We construct a Continuous Wavelet Transform (CWT) on the torus $\mathbb T^2$ following a group-theoretical approach based on the conformal group $SO(2,2)$. The Euclidean limit reproduces wavelets on the plane $\mathbb R^2$ with two…

Mathematical Physics · Physics 2014-11-04 Manuel Calixto , Julio Guerrero , Daniela Rosca

Many flexible parameterizations exist to represent data on the sphere. In addition to the venerable spherical harmonics, we have the Slepian basis, harmonic splines, wavelets and wavelet-like Slepian frames. In this paper we focus on the…

Data Analysis, Statistics and Probability · Physics 2013-06-14 Frederik J. Simons , Ignace Loris , Eugene Brevdo , Ingrid C. Daubechies

We develop a general notion of orthogonal wavelets `centered' on an irregular knot sequence. We present two families of orthogonal wavelets that are continuous and piecewise polynomial. We develop efficient algorithms to implement these…

Numerical Analysis · Mathematics 2014-09-17 Bruce W. Atkinson , Derek O. Bruff , Jeffrey S. Geronimo , Douglas P. Hardin

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