Logarithmic mathematical morphology: a new framework adaptive to illumination changes

A new set of mathematical morphology (MM) operators adaptive to illumination changes caused by variation of exposure time or light intensity is defined thanks to the Logarithmic Image Processing (LIP) model. This model based on the physics of acquisition is consistent with human vision. The fundamental operators, the logarithmic-dilation and the logarithmic-erosion, are defined with the LIP-addition of a structuring function. The combination of these two adjunct operators gives morphological filters, namely the logarithmic-opening and closing, useful for pattern recognition. The mathematical relation existing between ``classical'' dilation and erosion and their logarithmic-versions is established facilitating their implementation. Results on simulated and real images show that logarithmic-MM is more efficient on low-contrasted information than ``classical'' MM

A Pseudo-logarithmic Image Processing Framework for Edge Detection

Abstract. The paper presents a new [pseudo-] Logarithmic Model for Image Processing (LIP), which allows the computation of gray-level ad-dition, substraction and multiplication with scalars within a fixed gray-level range [0;D] without the use of clipping. The implementation of Laplacian edge detection techniques under the proposed model yields superior performance in biomedical applications as compared with the classical operations (performed either as real axis operations, either as classical LIP models).

General Adaptive Neighborhood Image Restoration, Enhancement and Segmentation

12 pagesInternational audienceThis paper aims to outline the General Adaptive Neighborhood Image Processing (GANIP) approach [1–3], which has been recently introduced. An intensity image is represented with a set of local neighborhoods defined for each point of the image to be studied. These so-called General Adaptive Neighborhoods (GANs) are simultaneously adaptive with the spatial structures, the analyzing scales and the physical settings of the image to be addressed and/or the human visual system. After a brief theoretical introductory survey, the GANIP approach will be successfully applied on real application examples in image restoration, enhancement and segmentation

Physical justifications and applications of the LIP model for the processing of transmitted light images

The Logarithmic Image Processing (LIP) mode{ is a mathematical framework which provides a special set of algebraic and functiona l operations for the processing of non-linear images and signals . In this paper, the initial ideas and some notions of the LIP mode l are firstly introduced . Then, it is shown that the physical absorption laws of monochromatic and panchromatic light waves ma y be expressed within this mathematical framework . The connections of the LIP model with several important physical characteristic s of transmitted light images are exposed . Finally, the effectiveness of the LIP model is illustrated in four image processing areas : illumination correction, background removing, dynamic range stabilization and control .Le modèle UP (Logarithmic Image Processing) est un cadre mathématique qui fournit un ensemble spécifique d'opérations algébriques et fonctionnelles pour le traitement d'images et de signaux non-linéaires. Dans cet article, les idées initiales et quelques notions du modèle LIP sont d'abord introduites. Ensuite, il est montré que les lois physiques d'absorption des ondes lumineuses monochromatiques et panchromatiques s'expriment dans ce cadre mathématique. Les relations des opérations de base du modèle LIP avec plusieurs caractéristiques importantes des images obtenues en lumière transmise sont alors exposées. Finalement, l'efficacité du modèle LIP est illustrée dans quatre domaines du traitement d'image: la correction de dérive d'éclairement, la suppression de fond, la stabilisation et le contrôle de dynamique

Détection de modulations linéaires de fréquence par traitement d'image sur la distribution de Wigner-Ville

Le but de cet article est de donner une nouvelle formulation du problème de détection dans le plan temps-fréquence en se basant sur la distribution de Wigner-Ville. Il s'agit ici de considérer la représentation temps-fréquence d'un signal comme une image sur laquelle il est possible de déterminer une technique de décision et d'estimation s'appuyant sur des méthodes propres au traitement d'image telles que l'ouverture morphologique, l'intercorrélation d'images et la transformée de Hough. Nous appliquons ces procédures de détection dans le cas de signaux composés de modulations linéaires de fréquence et nous les comparons par l'intermédiaire du tracé de leurs courbes COR

Three-grating monolithic phase-mask for the single-order writing of large-period gratings

A new type of achromatic high-efficiency monolithic phase mask is presented. The mask comprises three submicron period diffraction gratings at a single substrate side that create a purely single spatial frequency interferogram of large period. The optical scheme is that of an integrated Mach-Zehnder interferometer where all light circulation functions are performed by diffraction gratings. The paper describes the operation principle of the phase mask, the fabrication process, and its utilization in a write-on-the-fly scheme for the writing of a long, 2 µm-period grating

Dynamic Interferometry Lithography on a TiO 2

International audienceSolar electricity is one of the most promising renewable energy resources. However, the ratio module's cost/energy produced remains a major issue for classical photovoltaic energy. Many technologies have been developed to solve this problem, by using micro-or nanostructuring on the solar cell or on the module. These kinds of structuring are often used as antireflection and light-trapping tools. In the meantime, other solar technologies are considered, such as concentration photovoltaic modules. This article presents a module combining both approaches, that is, nanostructures and concentration, in order to increase the module's profitability. Sol-gel derived TiO 2 diffraction gratings, made by dynamic interferometric lithography, are added on the top of the glass cover to deflect unused light onto the solar cell, increasing the module efficiency

Acoustic-Labial Speaker Verification

This paper describes a multimodal approach for speaker verification. The system consists of two classifiers, one using visual features and the other using acoustic features. A lip tracker is used to extract visual information from the speaking face which provides shape and intensity features. We describe an approach for normalizing and mapping different modalities onto a common confidence interval. We also describe a novel method for integrating the scores of multiple classifiers. Verification experiments are reported for the individual modalities and for the combined classifier. The performance of the integrated system outperformed each sub-system and reduced the false acceptance rate of the acoustic sub-system from 2.3\% to 0.5\%