299 research outputs found
Handwritten and Printed Text Separation in Real Document
The aim of the paper is to separate handwritten and printed text from a real
document embedded with noise, graphics including annotations. Relying on
run-length smoothing algorithm (RLSA), the extracted pseudo-lines and
pseudo-words are used as basic blocks for classification. To handle this, a
multi-class support vector machine (SVM) with Gaussian kernel performs a first
labelling of each pseudo-word including the study of local neighbourhood. It
then propagates the context between neighbours so that we can correct possible
labelling errors. Considering running time complexity issue, we propose linear
complexity methods where we use k-NN with constraint. When using a kd-tree, it
is almost linearly proportional to the number of pseudo-words. The performance
of our system is close to 90%, even when very small learning dataset where
samples are basically composed of complex administrative documents.Comment: Machine Vision Applications (2013
High-resolution optical and SAR image fusion for building database updating
This paper addresses the issue of cartographic database (DB) creation or updating using high-resolution synthetic aperture radar and optical images. In cartographic applications, objects of interest are mainly buildings and roads. This paper proposes a processing chain to create or update building DBs. The approach is composed of two steps. First, if a DB is available, the presence of each DB object is checked in the images. Then, we verify if objects coming from an image segmentation should be included in the DB. To do those two steps, relevant features are extracted from images in the neighborhood of the considered object. The object removal/inclusion in the DB is based on a score obtained by the fusion of features in the framework of Dempster–Shafer evidence theory
Fusion d'images optique et radar à haute résolution pour la mise à jour de bases de données cartographiques
Cette thèse se situe dans le cadre de l'interprétation d'images satellite à haute résolution, et concerne plus spécifiquement la mise à jour de bases de données cartographiques grâce à des images optique et radar à haute résolution. Cette étude présente une chaîne de traitement générique pour la création ou la mise à jour de bases de données représentant les routes ou les bâtiments en milieu urbain. En fonction des données disponibles, différents scénarios sont envisagés. Le traitement est effectué en deux étapes. D'abord nous cherchons les objets qui doivent être retirés de la base de données. La seconde étape consiste à rechercher dans les images de nouveaux objets à ajouter dans la base de données. Pour réaliser ces deux étapes, des descripteurs sont construits dans le but de caractériser les objets d'intérêt dans les images d'entrée. L'inclusion ou élimination des objets dans la base de données est basée sur un score obtenu après fusion des descripteurs dans le cadre de la théorie de Dempster-Shafer. Les résultats présentés dans cette thèse illustrent l'intérêt d'une fusion multi-capteurs. De plus l'intégration aisée de nouveaux descripteurs permet à la chaîne d'être améliorable et adaptable à d'autres objets. ABSTRACT : This work takes place in the framework of high resolution remote sensing image analysis. It focuses on the issue of cartographic database creation or updating with optical and SAR images. The goal of this work is to build a generic processing chain to update or create a cartographic database representing roads and buildings in built-up areas. According to available data, various scenarios are foreseen. The proposed processing chain is composed of two steps. First, if a database is available, the presence of each database object is checked in the images. The second step consist of looking for new objects that should be included in the database. To determine if an object should be present in the updated database, relevant features are extracted from images in the neighborhood of the considered object. Those features are based on caracteristics of roads and buildings in SAR and optical images. The object removal/inclusion in the DB is based on a score obtained by the fusion of features in the framework of the Dempster-Shafer evidence theory. Results highlight the interest of multi sensor fusion. Moreover the chosen framework allows the easy integration of new features in the processing chai
Microstructure evolution of gold thin films under spherical indentation for micro switches contact applications
RF MEMS (Radio Frequency Micro Electro Mechanical System) switches are promising devices but their gold-on-gold contacts, assimilated for this work to a sphere / plane contact, represent a major reliability issue. A first step towards failure mechanism understanding is the investigation of the contact metal microstructure evolution under static and cyclic loading. After static and cyclic loading of sputtered gold thin films under spherical indentation, high resolution Electron Back Scatter Diffraction (EBSD) is used to investigate contact area. Grain rotation against {111} fiber texture of 1 μm thick sputtered gold thin film is a signature of plastic deformation. Grain rotation is observed above 1.6 mN under static loading by a spherical diamond indenter with 50 μm tip radius. A heterogeneity in grain rotation is observed corresponding to a more important plastic deformation in the middle of the indent than at the edge. A 30° Grain rotation is observed for a half million mechanical cycles under 300 μN load by a spherical gold tip (20 μm radius) due to cyclic work hardening. The same test in hot switching mode induces a grain growth in the contact area. Therefore thermal effects occurring during hot switching are underline
Origin of the double-peaked breakthrough curve in the Furfooz karst system: field data, scale model and numerical modelling
Origin of the double-peaked breakthrough curve in the Furfooz karst system: field data, scale model and numerical modelling
Direct Extraction of InP/GaAsSb/InP DHBT Equivalent-Circuit Elements From S-Parameters Measured at Cut-Off and Normal Bias Conditions
Receipt Dataset for Fraud Detection
International audienceThe aim of this paper is to introduce a new dataset initially created to work on fraud detection in documents. This dataset is composed of 1969 images of receipts and the associated OCR result for each. The article details the dataset and its interest for the document analysis community. We indeed share this dataset with the community as a benchmark for the evaluation of fraud detection approaches
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