The optimal processing of spectral data often requires specific pre-treatments. In the context of spectral discrimination, results can be greatly improved using the relevant pre-treatment. Most importantly, the pre-treatment mustbe suited to the nuisance variability that has to be removed. This study focuses on discrimination of weed and wheat usin...
Dans cet article, l'imagerie hyperspectrale Raman est utilisée pour la détection de comprimés contrefaits. Une première analyse qualitative (analyse en composante principale) basée sur la comparaison d'un composé authentique face à un comprimé suspect est réalisée. Le comprimé suspect est facilement identifié comme étant différent du comprimé de ré...
This article describes several linear pretreatments based on orthogonal projections. The main differences of these pretreatments lie in the way the information to be removed are identified, using calibration dataset, pure spectra, experimental designs or mathematical models. Removing all the undesired spectral information yields spectra proportiona...
L'azote est le facteur le plus limitant de la croissance des plantes, aussi sa mesure durant le cycle est un élément clé du contrôle des cultures. De nombreuses techniques de mesure non destructives basées sur les propriétés optiques de feuilles ont été proposées pour remplacer la méthode classique coûteuse et destructive de l'indice de nutrition a...
Following up on the success of previous chemometric challenges arranged during the annual congress organised by the French Chemometrics Society, the organisation committee decided to repeat the idea for the Chimiometrie 2007 event (http://www.chimiometrie.org/) held in Lyon, France (2930 November) by featuring another dataset on its website. As for...
[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]INSPIRE
Variable selection is of major interest for NIR calibration, either as a feature selection or for the design of multi-wavelength devices. Some dedicated methods have been developed in chemometrics, but a few of them addresses explicitly the case of multi-response calibration. Variable selection for NIR spectroscopy must face two problems: (1) the h...
Few methods are proposed in the litterature for coupling the spectral and the spatial dimension available on hyperspectral images. This paper proposes a generic segmentation scheme named butterfly based on an iterative process and a cross analysis of spectral and spatial information. Indeed, spatial and spatial structures are extracted in spatial a...
This article focuses the problem of the light absorption and diffusion of the bacterial concentration on the calibration of near infrared (NIR) spectroscopic methods for the monitoring of bioprocesses. The biomass or bacterial concentration produces multiplicative and additive effects on the NIR spectral measurements. The process monitored is a bat...
