Fusion of pixel-based and object-based features for classification of urban hyperspectral remote sensing data

Hyperspectral imagery contains a wealth of spectral and spatial information that can improve target detection and recognition performance. Typically, spectral information is inferred pixel-based, while spatial information related to texture, context and geometry are deduced on a per-object basis. Existing feature extraction methods cannot fully utilize both the spectral and spatial information. Data fusion by simply stacking different feature sources together does not take into account the differences between feature sources. In this paper, we propose a feature fusion method to couple dimension reduction and data fusion of the pixel- and object-based features of hyperspectral imagery. The proposed method takes into account the properties of different feature sources, and makes full advantage of both the pixel- and object-based features through the fusion graph. Experimental results on classification of urban hyperspectral remote sensing image are very encouraging

Tree species mapping by combining hyperspectral with LiDAR data

This study deals with data fusion of hyperspectral and LiDAR sensors for forest applications. In particular, the added value of different data sources on tree species mapping has been analyzed. A total of seven species have been mapped for a forested area in Belgium: Beech, Ash, Larch, Poplar, Copper beech, Chestnut and Oak. Hyperspectral data is obtained from the APEX sensor in 286 spectral bands. LiDAR data has been acquired with a TopoSys sensor Harrier 56 at full waveform. Confirming previous research [1], it has been found that airborne LiDAR data, when combined with hyperspectral data, can improve classification results. The novelty of this study is in the quantification of the contribution of the individual data sources and their derived parameters. LiDAR information was combined with the hyperspectral image in a data fusion approach. Different data fusion techniques were tested, including feature and decision fusion. Decision fucsion produced optimal results, reaching an overall accuracy of 96% (Kappa [3] of 0:95)

Effect of hyperspectral image denoising with PCA and total variation on tree species mapping using Apex Data

In this paper, the impact of image denoising on feature selection and tree species mapping accuracy is assessed. We apply a novel algorithm for hyperspectral (HS) image denoising using principal component analysis (PCA) and total variation (TV). The method is embedded in an object‐based classification framework and tested for complex forests with closed canopies and scarce reference data. Results show that, under the given conditions, HS image denoising is beneficial yielding stable mapping results with acceptable accuracy levels. Denoising also affected feature selection processing time with a time gain of 41.6%

Le Psaltérion à dix cordes de l'abbé Joachim de Flore

Joachim de Flore (1135-1202) est un auteur dont la pensée a marqué tout le Moyen-Age. Ses oeuvres sont en cours d'édition. Le Psalterium Decem Chordarum, déjà édité à Venise en 1527, n'avait pas été réédité depuis. Cette étude veut contribuer à son édition future en produisant une édition du texte vénitien, avec un apparat critique, un ensemble de mises au point face à une autre version, dite Padouane, et, en regard, sa traduction française annotée de façon à rendre le texte médiéval à un lecteur moderne. Cette thèse est aussi composée d'un tome introductif à la pensée de Joachim de Flore telle qu'elle se présente dans le Psalterium Decem Chordarum. C'est une théologie positive, accordant au voir une place importante, comme en témoigne l'hymne Visionem Ordiar, traduit ici pour la première fois. Elle recourt à des analogies trinitaires dont celles du Psaltérion et du triangle, que l'auteur adapte à son propos à l'aide de la théologie médiévale du nombre. Cette méthode donne à l'abbé Joachim de Flore les moyens de s'associer à la critique cistercienne des théologies abélardienne, porrétaine, et d'y ajouter sa propre critique de Pierre Lombard. La subordination de l'intelligence à la contemplation reste la méthode et le but employés. Ces points étant éclaircis, ce qui paraissait un ouvrage hermétique devient une longue contemplation de la Tri-Unité divine.STRASBOURG-B.N.U.S. (674821001) / SudocSudocFranceF