Majdi Khoudeir

Université de Poitiers | UP · Institut Universitaire de Technologie de Poitiers (IUTP)

Résoudre le problème de la stéréo-photométrie calibrée avec un nombre limité de lampes présente un grand intérêt pour des applications réelles. Aujourd'hui, les méthodes utilisant des réseaux de neurones sont devenues la norme. Dans ce cadre, nous proposons une nouvelle représentation basée sur les cartes de réflectance adaptée aux systèmes avec un...

Optical metrology includes a set of non-contact measurement methods to quantify shapes, surfaces, distances, deformations, displacements or colorimetry. Optical measurement methods have the advantage of being non-intrusive while allowing instantaneous measurements over extended areas. The applications of optical metrology concern all fields of engi...

From the point of view of image processing, road surfaces can be considered as textured images including both micro- and macro-textures. The extraction of relief is based on modeling the photometric behavior of the surface. As the Lambertian model is no longer valid and the relief extract is unreliable, one solution is the development of photometri...

This paper deals with print quality control through a spectral color measurement. The aim is to estimate the spectral reflectance curve of each pixel of a printed sheet for a spectral matching with the reference image. The proposed method consists to perform a spectral characterization of the complete chain which includes the printing system and a...

With the advent of the digital camera, a common popular imaging processing is high dynamic range (HDR) that aims to overcome the technological limitations of the irradiance sensor dynamic range. In this paper, we will present a new method to combine low dynamic range images (LDR) for HDR processing. This method is based on the theory of evidence. W...

In this paper, we propose a method for taking into account lighting conditions for photometric stereo. Indeed, with its classic form, the photometric stereo requires directional light sources and uniform intensity to determine the geometry and albedo of a surface from a reverse illumination model. These constraints are usually not realistic in prac...

In computer vision, the three-dimensional reconstruction by photometric stereo is common. The implementation of this method can be made from consumer equipment and the results are accurate for short acquisition time. However, the photometric stereo is regulated by application constraints such as the use of directional light sources. But the interes...

In classical photometric stereo (PS), a Lambertian surface is illuminated from three distant light sources to recover one normal direction per pixel of the input image. In continuous noiseless cases, PS allows us to reconstruct the textured surfaces in three-dimensions with a high degree of accuracy and a high resolution. In the real world, an imag...

Within the framework of the analysis of 3D textured surface through imageanalysis, we approach here the case of the 3D interfaces (fluid-solid) surfaces for the analysisof the local variations of their relief. Generally, the interaction between the light and these localvariations of the relief leads to a textured images of these surfaces. Our aim h...

This paper presents a self-learning system for automatic texture characterization and classification on ceramic pastes or fabrics and surfaces. The system uses Gabor filter as pre-processing methods with feature extraction possibilities. On these features it applies a linear discriminant analysis (LDA) and k-nearest neighbor classifiers (k-NN) with...

Textured surface analysis is essential for many applications. In this paper, we present a three-dimensional (3D) recovery approach for real textured surfaces based on photometric stereo. The aim is to be able to reconstruct the textured surfaces in 3D with a high degree of accuracy. For this, the proposed method uses a sequence of six images and a...

This paper shows the information criteria (IC) performances in feature selection framework. Feature selection aims to select a representative subset among a wide set of features. We apply this approach to classify an hand segmented image. The performance is tested using various feature selection schemes (SFS, SBS, SFFS and SBFS) to select the candi...

Cet articlé etudie le potentiel des critères d'information pour la sélection des variables. Ces critères sont intégrés dans des schémas de parcours de variables afin de sélectionner les sous-ensembles candidats. Le choix d'un sous-ensemble dépend de la qualité de l'approximation de la densité de probabilité de variables. En effet, nous avons adopté...

The analysis the macro and micro roughness of a surface by image processing is not common place. In this paper, we propose a new acquisition method of images with high quantification radiance adapted to photometric stereo to recover the surface shape. It allows to analyze simultaneously the high and low surface radiance variations. Our algorithm use...

In this paper we propose a new descriptor for human motion analysis. We try to recognize human motion represented by sequence of vector fields which are obtained with optical flow. Our method is based on an efficient measure of the similarity between two vector fields. This measure depends on the approximation of vector fields using projection onto...

Pasture species belonging to poaceae and fabaceae families constitute of essential elements to maintain natural and cultivated regions. Their balance and productivity are key factors for good functioning of the grassland ecosystems. The study is based on a process of image processing. First of all an individual signature is defined while considerin...

In this paper we present a new approach of image fusion at different spatial and spectral resolutions. Our approach uses supervised training to find the appropriate space representation. The aim is to generalize the different nonlinear color space transformations. To compare our approach with existing methods we have used assessment techniques of i...

Textured surface analysis is essential for many applications. We present a three-dimensional recovery approach for real textured surfaces based on photometric stereo. The aim is to be able to measure the textured surfaces with a high degree of accuracy. For this, we use a color digital sensor and principles of color photometric stereo. This method...

Road surface microtexture (sub-millimeter scale) is essential for pavement skid-resistance. However, its measurement is only possible in the laboratory on cores taken from trafficked roads, and is time consuming. For efficient road monitoring, it is necessary to develop faster methods usable on-site.Collaboration has been developed for 2 years betw...

Within the framework of the analysis of 3D textured environment through image analysis, we approach here the case of the rough surfaces for the analysis of the local variations of their relief. Generally, the interaction between the light and these local relief variations leads to a textured image of these surfaces. The proposed approach is an orig...

Nous proposons de décrire un algorithme original d'estimation de la profondeur d'une scène observée par une seule caméra couleur. Notre but est de mettre au point une méthode de reconstruction 3D de montages pour l'usinage, à faible coût, pour la surveillance de la validité des trajectoires d'usinage grande vitesse. L'algorithme suit la méthode que...

Rough surface relief extraction is generally made by a mechanical method using a tactile sensor or by using an auto-focus laser sensor. With these sensors we can estimate surface relief from the analysis of a series of profiles. Since these measurements spend a lot of time, we hope that we can determine the relief by image processing. Several metho...

The study of rough textured surface as road coverings, are generally made on grey level images. This suppose, that the variations of grey levels are representative of the local variations of the relief. This justified assumption, in the case of surfaces uniformly colored, finds its limit in the case when these surfaces present variations of color o...

The study of rough textured surfaces such as road coverings, is generally made on gray-level images. This supposes that the variations of gray levels are representative of the local variations of the relief. This assumption is justified, in the case of surfaces that are uniformly colored, but finds its limit in the case when these surfaces present...

Skid resistance, on which road safety depends, is closely related to the road surface texture and particularly to its microtexture. The microtexture is defined as surface irregularities whose height ranges from 0.001 mm to 0.5 mm and whose width is less than 0.5 mm (Alvarez and Mprel, 1994). The deterioration due to the road traffic, especially pol...

This study is carried out within the framework of the development of simulation systems of high frequency radio wave propagation (60 GHz) for wireless local area networks in an indoor environment. Thus the corresponding wavelength is in millimeters. At this frequency, in order to optimise models of radioelectric wave propagation, it is important to...

In this paper, we develop a new method for extracting invariant features for textured color surfaces moving in a 3D environment. This method is based on separation between chrominance which characterizes color of the surface, and intensity which characterizes the texture aspect. Invariant features for color are modeled by the first moments of the h...

We present a new method for computing the movement parameters of textured surfaces moving in a three dimensional environment. This method is based on the fact that the autocorrelation functions of an image and of its affine transformed version are linked by the same affine transformation applied to their axes. We use the Euler’s angles and the weak...

In this study, we propose an original method for a 3D reconstruction of the relief of a textured rough surfaces. This 3D reconstruction is obtained through the elaboration of a photometric model, which takes into account camera and light source positions according to the plan of the rough surface. The proposed model expresses the gray level on the...

For a transmission at 60 GHz inside the buildings, the models of propagation currently developed do not take into account the 3D roughness of surfaces under consideration. In this paper, we deal with the evaluation of the 3D roughness of surfaces in this kind of environment. An indoor environment includes different types of surfaces but the most re...

We develop a new histogram characterization method of colored textures, in order to recognize and classify them. This approach is simultaneously based on the use of the chromaticity diagram and the one-dimensional geometric moments. In the chromaticity diagram, we calculate the 1D distribution of wavelengths and purity factors. Then, color signatur...

The human visual system seems very powerful when it is a question to identifying an object or a portion of an object in movement, such as a textured surface moving in a 3D textured environment. In such a situation, the visual impression of an observer depends on many factors, including the nature of relative movement between the scene and the obser...

Car road holding is linked to many factors including adherence, which is strongly related to the roughness of the road coating and of its evolution under the effect of traffic. Traffic induces a progressive wear of the road surface which results in a modification of its local relief and of its roughness. We study road coverings in order to know the...

In this article, we develop a new method of characterization of colored random textures. This method is based on the use of the chromaticity diagram combined with the 1D-geometric moments. In CIE XYZ color space, each pixel of an image is associated with a point within chromatic space, in which a color is characterized by its wavelength and its pur...

The study of rough textured surface are generally made on grey level images. These studies suppose, that the variations of grey levels are representative of local variations of relief. This assumption, in the case of uniformly colored rough surfaces, finds its limit in the case when these rough surfaces present variations of color or aspect. The co...

A new method for invariant feature extraction on textured images undergoing affine transformations is presented. This is performed by transformation of the autocorrelation function (ACF) followed by determination of an invariant criterion which is the sum of the coefficients of the discrete correlation matrix. Experimental results support the effec...

Un problème classique en analyse d'image est d'obtenir une modélisation caractéristique d'images texturées. L'utilisation d'un modèle AR-2D fournit souvent des solutions efficaces. Cependant, l'identification des coefficients d'un tel modèle est assujettie à l'hypothèse de stationnarité du signal. Pour résoudre ce problème, nous considérons la dist...

Les différentes méthodes de stéréovision monoculaire existantes reposent sur l'exploitation des caractéristiques des contours d'objets contenus dans deux images d'une même scène 3D. Ces méthodes sont difficilement exploitables en présence d'objets texturées. Nous proposons une méthode permettant la mesure, par exploitation du flou optique, de la pr...

This paper concern the matching phase needed in binocular stereovision, for object location in 3D scene. We present here a new matching approach exploiting line moments. We show that the relation between the line moments having (0+q) order of a segment of the image on the right and the same order moment of the image on the left keep a constant valu...

La méthode de stéréovision monoculaire passive proposée exploite deux images floues d'une même scène 3D, acquises d'un même point de vue mais avec une ouverture de l'iris différente. Le système optique ne possédant qu'un seul plan net à une profondeur donnée, les images présentent un flou lié à la profondeur. La modélisation de la réponse impulsion...

Within the framework of the analysis of 3D textured surface through image analysis, we approach here the case of the 3D interfaces (fluid-solid) surfaces for the analysis of the local variations of their relief. Generally, the interaction between the light and these local variations of the relief leads to a textured images of these surfaces. Our ai...

Dans le cadre de l'analyse d'environnement 3D texturés par traitement d'images, nous abordons ici le cas des surfaces rugueuses pour l'analyse des variations locales de leur relief à une échelle fine. En général, l'interaction entre la lumière et ces variations locales du relief se traduit par un aspect texturé des images de ces surfaces. L'objecti...