Fuzzy Contrast Improvement for Low Altitude Aerial Images

International audiencePrecision agriculture is becoming very important in improving food security. Unmanned Aerial Vehicles (UAVs) have higher possibilities in this way, improving real time data gathered with aerial sensors. Fuzzy techniques have proved to be highly effective in managing vagueness and ambiguity. The unmanned helicopters are highly valuable due to the level of maneuverability that they possess. We believe that many different degrees of autonomy and functionalities of UAVs will be useful in agriculture. We present a new process to extract data from aerial images that comes from low altitude UAVs. We combined NDVI algorithm output with the RSWHE-M method on grey scaled images. Primary results show that our method extracts images that are visually acceptable to human eye and have a natural appearance

Novel Approach for Detection and Removal of Moving Cast Shadows Based on RGB, HSV and YUV Color Spaces

Cast shadow affects computer vision tasks such as image segmentation, object detection and tracking since objects and shadows share the same visual motion characteristics. This unavoidable problem decreases video surveillance system performance. The basic idea of this paper is to exploit the evidence that shadows darken the surface which they are cast upon. For this reason, we propose a simple and accurate method for detection of moving cast shadows based on chromatic properties in RGB, HSV and YUV color spaces. The method requires no a priori assumptions regarding the scene or lighting source. Starting from a normalization step, we apply canny filter to detect the boundary between self-shadow and cast shadow. This treatment is devoted only for the first sequence. Then, we separate between background and moving objects using an improved version of Gaussian mixture model. In order to remove these unwanted shadows completely, we use three change estimators calculated according to the intensity ratio in HSV color space, chromaticity properties in RGB color space, and brightness ratio in YUV color space. Only pixels that satisfy threshold of the three estimators are labeled as shadow and will be removed. Experiments carried out on various video databases prove that the proposed system is robust and efficient and can precisely remove shadows for a wide class of environment and without any assumptions. Experimental results also show that our approach outperforms existing methods and can run in real-time systems

For a Data-Driven Interpretation of Rules wrt GMP Conclusions in Abductive Problems

International audienceAbductive reasoning is an explanatory process in which potential causes of an observation are unearthed. In its classical – crisp – version it offers little lattitude for discovery of new knowledge. Placed in a fuzzy context, abduction can explain observations which did not, originally, exactly match the expected conclusions. Studying the effects of slight modifications through the use of linguistic modifiers was, therefore , of interest in order to describe the extent to which observations can be modified yet still explained and, possibly, create new knowledge. We will concentrate on the formal definition of fuzzy abduction given by Mellouli and Bouchon-Meunier. Our results will be shown to be incompatible with established theories. We will show where this incompatibility comes from and derive from it a selection of fuzzy implication , based on observable data

Incertain et inconnu, deux facettes de la cotation

International audienceLa génération automatique de connaissances s'assortit généralement d'une mesure de confiance. Les systèmes d'apprentissagé evaluent leurs performances en fonction des standards et de leurs pertinences. Les outils de recherche d'informations classent leurs résultats selon diverses stratégies, en fonction du contexte d'utilisation. Cette nécessiténécessité´nécessitéémane autant des algorithmes, des modèles que des faits eux-mêmes. Cependant, la majorité des degrés de confiance affectésaffectés`affectésà des informa-tions le sont demanì ere globale. Nous percevons la cotation comme la projection de différentes dimensions d'in-certitude ou d'imperfections sur la donnée elle-même. PourêtrePourˆPourêtre utile, la cotation doitêtredoitˆdoitêtre compréhensible. Nous nous proposons donc de focaliser notre attention sur la représentation de la cotation. Pour la favoriser, nous proposons de distinguer la cotation indéterminée de sonévaluationson´sonévaluation impossible. Mots-clés : Cotation d'information, incertitude, logique multivalente, ´ evaluation impossible

Vers une classification de problèmes abductifs en fonction d'observations possibles

National audienceIn a context where all knowledge is given by rules and the only observable data lies in the solution space, inferring potential explanations for a given observation is not an easy task, even if the observation is close to the expected conclusion. This is why we originally considered the impact of hedges on observations in abductive reasoning. Extending a formal definition of fuzzy abduction given by Mellouli and Bouchon-Meunier, we show that some modifiers are inexplicable for a given implication. Instead of reconsidering our original rule as being incompatible with the data, we choose to question the selection of fuzzy implication. Indeed, we will show that possible conclusions are dependent on the implication operator, as is the semantic interpretation of the associated rules.Dans un contexte où la connaissance émane de règles et que les seules observations possibles proviennent de l’espace des conclusions, l’inf́erence d’explications potentielles n’est pas aisée. Ceci explique pourquoi nous nous sommes intéressés aux modificateurs linguistiques dans l’abduction floue. En étendant des résultats de Mellouli et Bouchon-Meunier, nous montrons que des modificateurs sont inexplicables avec certaines implications. Au lieu de revoir notre règle originelle comme incompatible avec les données, nous questionnons le choix de l’opérateur d’implication. Nous montrerons que les conclusions acceptables dépendent de l’implication, comme l’interprétation sémantique des règles correspondantes

AGENT-BASED MODELING FOR TRAFFIC SIMULATION

In  this  paper  we  develop  a  multi-agent  based  traffic  simulator  by  considering traffic  flows as emergent phenomena. The main  problem  of  agent-based  traffic  simulation  is how  to  reproduce  realistic  patterns  of  traffic  flow  at  both macroscopic and microscopic. The objective of simulation is a scenario of  traffic generated by the model  that should provide  the illusion of a real road scenario

La gestion des incertitudes dans les systèmes intelligents

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Supervised learning using modifiers: application in colorimetrics

International audienceSummary form only given. We present a method for a learning process that we apply to a colorimetric application. In the application, we associate colours to linguistic expressions and these associations can be changed thanks to our learning process. The method consists of memorizing the meaning of the linguistic expressions according to a learning done thanks to the user. To perform this, we use a graph and some linguistic modifiers (such as /spl bsol/much more", /spl bsol/a bit less", etc.) in order to store the acquired knowledge and its associated nuance. Then, we introduce new operations on linguistic modifiers in order to include an information intensity notion in the graph and to finally restore this intensity to the user in a coherent way. Towards this goal, we employ the notions of mathematical composition and inverse

Le traitement de l'incertain par une Approche Qualitative

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Le traitement de l'incertain par une Approche Qualitative

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