Browsing graphics without prior knowledge

In this paper, we present a system to browse a set of graphical documents without prior knowledge of their content. This system relies on a new structural method locating regions potentially embedding a symbol, using an unsupervised reconstruction of the documents from their representation as chain of points. The method is complemented by a querying mechanism that retrieves from these regions those that are the most similar to a given input symbol. This mechanism uses a specific user feedback scheme to improve the accuracy of the retrieval

A Few Steps Towards On-the-Fly Symbol Recognition with Relevance Feedback

http://www.springerlink.com/This paper presents some first steps in building an interactive system which allows a user to efficiently browse a large set of scanned documents, without prior knowledge on the content of these documents, and retrieving symbols of interest to him personally, through a relevance feedback mechanism

Reconnaissance de symboles graphiques par le biais de l'intégrale de Choquet

International audiencenous présentons dans cet article trois modèles pour extraire un sous-ensemble de règles de décision et leur agrégation en une règle de décision unique par le biais de l'intégrale de Choquet. Nous nous intéressons à des applications où l'on possède peu d'échantillons représentatifs par classe. Les approches que nous avons construites sont de type global, par classe ou bi-classes. Des applications sur des données réelles attestent de la robustesse de nos méthodes et leur adaptabilité

Principes et mise en oeuvre de l'interopérabilité dans le système d'analyse de documents Qgar

Colloque avec actes et comité de lecture. Internationale.International audienceCet article décrit d'abord brièvement la plateforme logicielle d'analyse de documents Qgar, son architecture, ses grandes composantes, ainsi que les choix techniques retenus pour les outils et les formats utilisés. Il décrit ensuite plus précisément la solution mise en oeuvre pour faciliter l'interopérabilité au sein de la plate-forme, c'est-à-dire l'intégration des applications réalisées avec les briques logicielles fournies par la bibliothèque du système et l'intégration des applications importées. Chaque application est associée à un document XML qui fournit ses caractéristiques : description à l'usage des clients, types et valeurs des paramètres. Bien que simple et pragmatique, cette solution se révèle performante, pour exporter des applications Qgar ou pour importer des applications tierces, comme le montrent les exemples donnés

A feature selection method based on Choquet Integral and Typicality Analysis

ISBN: 1-4244-1210-2International audienceIn this paper, we present an iterative feature selection method based on feature typicality and interactivity analysis. The aim of such a method is to enhance model interpretability by selecting the best significant features among a list extracted from images. The inference mechanism uses a fuzzy linguistic rule-based system. In the presented application, we apply this method to wood defect classification. Nowadays, feature selection is expertise-driven and most of the time, expert uses features by habits which not always represent the best ones to use. The proposed method aims to replace expert selection by automatically choosing the most adapted features to the recognition problem

On Determining Suitable Subsets of Decision Rules using Choquet Integral

International audienceWe present an approach to automatically extract a pertinent subset of soft output classifiers, and to aggregate them into a global decision rule using the Choquet integral. This approach relies on two key points. The first is a learning algorithm that uses a measure of the confusion between the categories to be recognized. The second is a selection scheme that discards weak or redundant decision rules, keeping only the most relevant subset. An experimental study, based on real world data, is then described. It analyzes the improvements achieved by these points first when used independently, then when combined together

Selection of Suitable Set of Decision Rules using Choquet Integral, Statistic Pattern Recognition

International audienc

Serial time-resolved crystallography of photosystem II using a femtosecond X-ray laser

Photosynthesis, a process catalysed by plants, algae and cyanobacteria converts sunlight to energy thus sustaining all higher life on Earth. Two large membrane protein complexes, photosystem I and II (PSI and PSII), act in series to catalyse the light-driven reactions in photosynthesis. PSII catalyses the light-driven water splitting process, which maintains the Earth’s oxygenic atmosphere1. In this process, the oxygen-evolving complex (OEC) of PSII cycles through five states, S0 to S4, in which four electrons are sequentially extracted from the OEC in four light-driven charge-separation events. Here we describe time resolved experiments on PSII nano/microcrystals from Thermosynechococcus elongatus performed with the recently developed2 technique of serial femtosecond crystallography. Structures have been determined from PSII in the dark S1 state and after double laser excitation (putative S3 state) at 5 and 5.5 Å resolution, respectively. The results provide evidence that PSII undergoes significant conformational changes at the electron acceptor side and at the Mn4CaO5 core of the OEC. These include an elongation of the metal cluster, accompanied by changes in the protein environment, which could allow for binding of the second substrate water molecule between the more distant protruding Mn (referred to as the ‘dangler’ Mn) and the Mn3CaOx cubane in the S2 to S3 transition, as predicted by spectroscopic and computational studies3, 4. This work shows the great potential for time-resolved serial femtosecond crystallography for investigation of catalytic processes in biomolecules