Textural ordination based on Fourier spectral decomposition: a method to analyze and compare landscape patterns

Couteron Pierre, Barbier Nicolas, Gautier Denis. 2006. Textural ordination based on Fourier spectral decomposition: a method to analyze and compare landscape patterns. Landscape Ecology, 21 (4) : 555-567.

Liste HCERES des revues (en SHS) : oui

Thème(s) HCERES des revues (en SHS) : Géographie-Aménagement-Urbanisme-Architecture

Résumé : We propose an approach to texture characterization and comparison that directly uses the information of digital images of the earth surface without requesting a prior distinction of structural 'patches'. Digital images are partitioned into square 'windows' that define the scale of the analysis and which are submitted to the two-dimensional Fourier transform for extraction of a simplified textural characterization (in terms of coarseness) via the computation of a 'radial' power spectrum. Spectra computed from many images of the same size are systematically compared by means of a principal component analysis (PCA), which provides an ordination along a limited number of coarseness vs. fineness gradients. As an illustration, we applied this approach to digitized panchromatic air photos depicting various types of land cover in a semiarid landscape of northern Cameroon. We performed 'textural ordinations' at several scales by using square windows with sides ranging from 120 m to 1 km. At all scales, we found two coarseness gradients (PCA axes) based on the relative importance in the spectrum of large (> 50 km [exponent) -1), intermediate (30-50 km [exponent)-1), small (10-25 km [exponent) -1) and very small (<10 km [exponent) -1) spatial frequencies. Textural ordination based on Fourier spectra provides a powerful and consistent framework to identifying prominent scales of landscape patterns and to compare scaling properties across landscapes.

Mots-clés Agrovoc : modèle mathématique, télédétection, cartographie, analyse d'image, paysage

Mots-clés géographiques Agrovoc : Sahel, Cameroun

Classification Agris : U30 - Méthodes de recherche
U10 - Informatique, mathématiques et statistiques
P31 - Levés et cartographie des sols

Champ stratégique Cirad : Hors axes (2005-2013)

Auteurs et affiliations

• Couteron Pierre, Institut français de Pondichéry (IND)
• Barbier Nicolas, ULB (BEL)
• Gautier Denis, CIRAD-FORET-UPR Ressources forestières (MLI) ORCID: 0000-0001-7648-1881

Source : Cirad - Agritrop (https://agritrop.cirad.fr/560148/)

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