Vers une plate-forme d'indexation interactive de documents

International audienceCet article décrit comment le logiciel AGORA a été amélioré afin de tenir compte des retours d'usages obtenus lors d'une utilisation intensive de la version 1 du logiciel par les etudiants et les membres du CESR. La nouvelle version propose un module d'assistance aux utiilisateurs afin de rendre plus simple, conviviale et intuitive la phase de mise en place des scenarios d'indexation. L'utilisateur (non expert en traitement d'images) construit simplement des scénarios permettant d'étiqueter, de fusionner et de supprimer les éléments de contenus à indexer. Il localise ainsi les entités qui l'intéressent en ignorant les autres régions de l'image. Les scénarios élaborés peuvent ensuite être sauvegardés, modifiés et appliqués sur différentes images lors de traitements par lots

A robust braille recognition system

Braille is the most effective means of written communication between visually-impaired and sighted people. This paper describes a new system that recognizes Braille characters in scanned Braille document pages. Unlike most other approaches, an inexpensive flatbed scanner is used and the system requires minimal interaction with the user. A unique feature of this system is the use of context at different levels (from the pre-processing of the image through to the post-processing of the recognition results) to enhance robustness and, consequently, recognition results. Braille dots composing characters are identified on both single and double-sided documents of average quality with over 99% accuracy, while Braille characters are also correctly recognised in over 99% of documents of average quality (in both single and double-sided documents)

Attention and Emotion Influence the Relationship Between Extraversion and Neural Response

Extraversion has been shown to positively correlate with activation within the ventral striatum, amygdala and other dopaminergically innervated, reward-sensitive regions. These regions are implicated in emotional responding, in a manner sensitive to attentional focus. However, no study has investigated the interaction among extraversion, emotion and attention. We used fMRI and dynamic, evocative film clips to elicit amusement and sadness in a sample of 28 women. Participants were instructed either to respond naturally (n = 14) or to attend to and continuously rate their emotions (n = 14) while watching the films. Contrary to expectations, striatal response was negatively associated with extraversion during amusement, regardless of attention. A negative association was also observed during sad films, but only when attending to emotion. These findings suggest that attentional focus does not influence the relationship between extraversion and neural response to positive (amusing) stimuli but does impact the response to negative (sad) stimuli

Effects of weight loss and seafood consumption on inflammation parameters in young, overweight and obese European men and women during 8 weeks of energy restriction

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldBackground/Objectives:In vitro studies have shown that long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) can affect inflammation; however, results from intervention studies in overweight or obese individuals are contradicting. The aim of this study was to investigate the effects of weight loss and seafood consumption on inflammation parameters during energy restriction.Subjects/Methods:In this 8-week intervention trial, 324 subjects (aged 20-40 years, body mass index 27.5-32.5 kg/m(2) from Iceland, Spain and Ireland) were randomized to one of four energy-restricted diets (-30% relative to estimated requirements): salmon (3 x 150 g/week, 2.1 g LC n-3 PUFA per day); cod (3 x 150 g/week, 0.3 g LC n-3 PUFA per day); fish oil capsules (1.3 g LC n-3 PUFA per day); and control (sunflower oil capsules, no seafood). Body weight, high-sensitivity C-reactive protein (CRP), interleukin-6 (IL-6), glutathione reductase and prostaglandin F2 alpha (PGEF2alpha) were measured at baseline and end point.Results:Subjects experienced weight loss (-5.2+/-3.2 kg, P<0.001). Taken together for all subjects, there were significant decreases in all inflammation parameters. On a group level, salmon consumption was most effective, three of the four inflammation parameters decreased in the salmon group (high-sensitivity CRP=-32.0%; IL-6=-18.4%; PGEF2alpha=-18.5%; all P<0.05). Cod consumption decreased high-sensitivity CRP and IL-6 (-21.5 and -10.8%, respectively, both P<0.05). Changes in the other two groups were not significant, which can be partly explained by the large s.d.Conclusions:The mean concentrations of inflammation parameters decreased during a period of weight loss and dietary intervention. In our study, salmon consumption was most effective, three of the four measured inflammation parameters decreased significantly in the salmon group

Interactive segmentation and analysis of historical printed documents

In this paper, we first precise the main error sources from classical methods of structural page layout analysis based on a study of the specificity of old printed books. We show that each type of methods (bottom-up and top-down) provides different kinds of information that should not be ignored to obtain both a generic method and good segmentation results. Then, we propose to use a hybrid segmentation algorithm. We build two maps : a shape map that focuses on connected components and a background map that provides information on white areas corresponding to block separation in the page. Then, using this first segmentation, a classification of the extracted blocks can be achieved according to scenarios built by the user. These scenarios are defined very simply during an interactive stage allowing the users to produce processing sequences adapted to the different kinds of images they can meet and to their needs. The method gives very good results while the setting of parameters is easy and not sensitive to low variations.Après avoir caractérisé les spécificités de mise en page dans les ouvrages imprimés anciens, nous montrons par une campagne d’expérimentations que les méthodes ascendantes et descendantes d’extraction de la structure physique apportent des informations différentes qu’il ne faut pas ignorer lorsque l’on désire segmenter de manière optimale des documents anciens. Les tests réalisés mettent également en évidence les sources d’erreurs des méthodes traditionnelles. Partant de ces constatations, notre proposition consiste à utiliser un algorithme de segmentation hybride basé sur la construction de deux représentations de l’image : une carte des formes qui se focalise sur les composantes connexes présentes dans l’image et une carte du fond qui fournit de l’information sur les espaces blancs séparant les blocs constituant la page. Ensuite, sur la base de la segmentation obtenue à l’aide de cette méthode, une classification des blocs extraits peut être réalisée selon des scénarios que l’utilisateur met en place en fonction de ses besoins. Ces scénarios sont définis simplement grâce à une phase d’interaction entre l’utilisateur et le système et permettent de concevoir des chaînes de traitements adaptées aux différents types d’images que l’on peut rencontrer

Visualising apoptosis in live zebrafish using fluorescence lifetime imaging with optical projection tomography to map FRET biosensor activity in space and time

Fluorescence lifetime imaging (FLIM) combined with optical projection tomography (OPT) has the potential to map Förster resonant energy transfer (FRET) readouts in space and time in intact transparent or near transparent live organisms such as zebrafish larvae, thereby providing a means to visualise cell signalling processes in their physiological context. Here the first application of FLIM OPT to read out biological function in live transgenic zebrafish larvae using a genetically expressed FRET biosensor is reported. Apoptosis, or programmed cell death, is mapped in 3-D by imaging the activity of a FRET biosensor that is cleaved by Caspase 3, which is a key effector of apoptosis. Although apoptosis is a naturally occurring process during development, it can also be triggered in a variety of ways, including through gamma irradiation. FLIM OPT is shown here to enable apoptosis to be monitored over time, in live zebrafish larvae via changes in Caspase 3 activation following gamma irradiation at 24 hours post fertilisation. Significant apoptosis was observed at 3.5 hours post irradiation, predominantly in the head region

Interpretation of technical drawings using perceptive cycles starting with its global perception

In this paper, we propose a new method for automatic understanding of technical documents . In the case we are concerned with , technical documents are essentially constituted of graphics (lines, filled shapes, text, . . .) and have been drawn either by hand o r with the help of an editor. The chosen architecture allows to extract, from the document, the graphic and alphanumeric informatio n in order to rebuild the semantic associated to the different objects in the drawing and to their relationships . To realize this work , we have tried to automatise natural techniques normally associated with human perception . . A first stage of global perception of the document is realized, using a limited number of elementary primitives : the Pixel, th e Vector and the Quadrilateral, to obtain a first representation of the document . This first representation allows to depict correctl y several kinds of technical documents (diagrams, cadastral maps, musical scores, . . .) . This representation will provide a precis e description of all the shapes from the original document (binary images) along the different levels of the analysis . . Next, the dual use of this representation of the document and of a multi-specialist system allows to improve the local analysi s during all the reading and understanding steps . A mechanism of «perceptive cycles » allows the different specialists to cooperate . Each specialist possesses some elementary, precise and sufficient information in some particular domains : extraction of text, curves, mechanical elements and it uses the global vision to focus its attention on some places of the image . The hypotheses that the specialists interjected are verified and induce the evolution of the representation of the document . This step of progressive reading has been tested in the particular case of kinetic diagrams . The entire system, using six different specialists, seems to b e perfectly suited to this kind of document . This method is quite different from those using classical procedure : pre-processing - segmentation - analysis - recognition . Every step of the process brings some new information that is used either to confirm a previous hypothesis or states a new one until th e total understanding of the document is achieved .Nous présentons, dans cet article, un système de lecture automatique de documents techniques. Les dessins techniques, au sens où nous l'entendons par la suite, sont des documents essentiellement graphiques (constitués de traits, de formes pleines, de texle produits par un dessinateur, à la main ou avec l'aide d'un système d'édition. L'architecture que nous avons choisie et développée permet d'extraire l'information graphique et alphanumérique du document pour reconstituer la sémantique associée aux différents objets du dessin et à leurs relations. En nous inspirant des connaissances acquises sur les mécanismes de la vision humaine, nous avons élaboré une méthode comportant deux phases : Durant une première phase de perception globale, une représentation initiale du document est obtenue à l'aide d'un nombre limité de primitives : le Pixel, le Vecteur, le Quadrilatère. Le choix de ces primitives permet à cette représentation de s'adapter à la description de documents techniques de types variés (plans, cadastres, partitions musicales,...). Cette représentation, bien que fondée sur des primitives élémentaires, fournit une description précise de toutes les formes,du document initial (image binaire). Outre leur adéquation aux formes à décrire, ces primitives constituent la base de la structure de données qui nous permettra de définir une représentation efficace des connaissances acquises sur le document durant l'analyse. Ensuite, l'utilisation duale d'un système multi-spécialistes et de la représentation préalablement construite permet, au cours d'une phase de lecture et d'interprétation, d'utiliser les données fournies par la vision globale pour réaliser les analyses locales. Un mécanisme de "cycles perceptifs" permet aux différents spécialistes de coopérer pour réduire au maximum les erreurs d'analyse et aboutir à une interprétation plus robuste. Chaque spécialiste réalise une tâche précise telle que, par exemple, la détection du texte, des courbes, des éléments mécaniques ou la reconstruction 3D du mécanisme. Tous utilisent la représentation construite pour focaliser leur attention sur des zones précises de l'image qu'ils étudient en détail. En fin de chaque cycle, la complétude de la compréhension du document est vérifiée et un nouveau cycle d'activation des spécialistes approfondit, si nécessaire, l'interprétation. Cette phase de lecture progressive a été mise en place pour le cas particulier des plans cinématiques mécaniques. Le système obtenu comporte alors six spécialistes et s'accorde parfaitement au traitement de ce type de document. Les exécutions continues et entrelacées des différents spécialistes permettent de réaliser des analyses contextuelles par segmentations successives augmentant ainsi l'interaction et l'efficacité du système. Grâce à cette démarche, nos travaux se distinguent de ceux employant la chaîne habituelle de traitements : pré-traitements -segmentation - analyse - reconnaissance. Notre système s'efforce, dans la vision globale, d'extraire des connaissances puis, à partir des informations possédées sur le document, d'extraire des formes de manière hiérarchique et réfléchie, et il les transcrit dans une représentation évolutive décrivant à chaque instant l'état du contexte d'interprétation

Analyse des orientations pour la caractérisation d'images de documents de la renaissance

Cet article présente une nouvelle méthode de caractérisation d'images de documents imprimés datant de la Renaissance. Notre approche se base sur une extraction des différentes orientations présentes sur la totalité de la surface de la page et qui sont caractéristiques de la présence de différentes entités textuelles, ou graphiques (incluant les enluminures, les ornements et bandeaux, les lettrines, ainsi que diverses illustrations). Cette caractérisation s'appuie sur le calcul et l'exploitation de la fonction d'autocorrélation qui a la particularité, lorsqu'elle est estimée sur une zone de texte ou de dessin, de générer une signature unique facilement identifiable. Ce choix nous permet de séparer le texte des dessins, tout en minimisant la quantité d'a priori relatif aux images traitées

Accelerated optical projection tomography applied to in vivo imaging of zebrafish

Optical projection tomography (OPT) provides a non-invasive 3-D imaging modality that can be applied to longitudinal studies of live disease models, including in zebrafish. Current limitations include the requirement of a minimum number of angular projections for reconstruction of reasonable OPT images using filtered back projection (FBP), which is typically several hundred, leading to acquisition times of several minutes. It is highly desirable to decrease the number of required angular projections to decrease both the total acquisition time and the light dose to the sample. This is particularly important to enable longitudinal studies, which involve measurements of the same fish at different time points. In this work, we demonstrate that the use of an iterative algorithm to reconstruct sparsely sampled OPT data sets can provide useful 3-D images with 50 or fewer projections, thereby significantly decreasing the minimum acquisition time and light dose while maintaining image quality. A transgenic zebrafish embryo with fluorescent labelling of the vasculature was imaged to acquire densely sampled (800 projections) and under-sampled data sets of transmitted and fluorescence projection images. The under-sampled OPT data sets were reconstructed using an iterative total variation-based image reconstruction algorithm and compared against FBP reconstructions of the densely sampled data sets. To illustrate the potential for quantitative analysis following rapid OPT data acquisition, a Hessian-based method was applied to automatically segment the reconstructed images to select the vasculature network. Results showed that 3-D images of the zebrafish embryo and its vasculature of sufficient visual quality for quantitative analysis can be reconstructed using the iterative algorithm from only 32 projections-achieving up to 28 times improvement in imaging speed and leading to total acquisition times of a few seconds