Multiscale and Anisotropic Characterization of Images Based on Complexity: an Application to Turbulence - Pôle AI & Ocean
Pré-Publication, Document De Travail Année : 2023

Multiscale and Anisotropic Characterization of Images Based on Complexity: an Application to Turbulence

Résumé

This article presents a multiscale, non-linear and directional statistical characterization of images based on the estimation of the skewness, flatness, entropy and distance from Gaussianity of the spatial increments. These increments are characterized by their magnitude and direction; they allow us to characterize the multiscale properties directionally and to explore anisotropy. To describe the evolution of the probability density function of the increments with their magnitude and direction, we use the skewness to probe the symmetry, the entropy to measure the complexity, and both the flatness and distance from Gaussianity to describe the shape. These four quantities allow us to explore the anisotropy of the linear correlations and non-linear dependencies of the field across scales. First, we validate the methodology on two-dimensional synthetic scale-invariant fields with different multiscale properties and anisotropic characteristics. Then, we apply it on two synthetic turbulent velocity fields: a perfectly isotropic and homogeneous one, and a channel flow where boundaries induce inhomogeneity and anisotropy. Our characterization unambiguously detects the anisotropy in the second case, where our quantities report scaling properties that depend on the direction of analysis. Furthermore, we show in both cases that turbulent velocity fluctuations are always isotropic, when the mean velocity profile is adequately removed.
Fichier principal
Vignette du fichier
TurbAnisotropicEntropy_HAL_29082023.pdf (12.83 Mo) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-04190553 , version 1 (29-08-2023)
hal-04190553 , version 2 (12-01-2024)

Identifiants

Citer

Carlos Granero-Belinchon, Stéphane G. Roux, Nicolas B. Garnier. Multiscale and Anisotropic Characterization of Images Based on Complexity: an Application to Turbulence. 2023. ⟨hal-04190553v1⟩
113 Consultations
66 Téléchargements

Altmetric

Partager

More