• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 18
  • 7
  • 3
  • 3
  • 1
  • Tagged with
  • 34
  • 14
  • 9
  • 8
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Evaluation of biometric security systems against artificial fingers

Blommé, Johan January 2003 (has links)
Verification of users’ identities are normally carried out via PIN-codes or ID- cards. Biometric identification, identification of unique body features, offers an alternative solution to these methods. Fingerprint scanning is the most common biometric identification method used today. It uses a simple and quick method of identification and has therefore been favored instead of other biometric identification methods such as retina scan or signature verification. In this report biometric security systems have been evaluated based on fingerprint scanners. The evaluation method focuses on copies of real fingers, artificial fingers, as intrusion method but it also mentions currently used algorithms for identification and strengths and weaknesses in hardware solutions used. The artificial fingers used in the evaluation were made of gelatin, as it resembles the surface of human skin in ways of moisture, electric resistance and texture. Artificial fingers were based on ten subjects whose real fingers and artificial counterpart were tested on three different fingerprint scanners. All scanners tested accepted artificial fingers as substitutes for real fingers. Results varied between users and scanners but the artificial fingers were accepted between about one forth and half of the times. Techniques used in image enhancement, minutiae analysis and pattern matching are analyzed. Normalization, binarization, quality markup and low pass filtering are described within image enhancement. In minutiae analysis connectivity numbers, point identification and skeletonization (thinning algorithms) are analyzed. Within pattern matching, direction field analysis and principal component analysis are described. Finally combinations of both minutiae analysis and pattern matching, hybrid models, are mentioned. Based on experiments made and analysis of used techniques a recommendation for future use and development of fingerprint scanners is made.
22

Segmentation de Processus de Comptage et modèles Dynamiques / Segmentation of counting processes and dynamical models

Alaya, Elmokhtar Ezzahdi 27 June 2016 (has links)
Dans la première partie de cette thèse, nous cherchons à estimer l'intensité d'un processus de comptage par des techniques d'apprentissage statistique en grande dimension. Nous introduisons une procédure d'estimation basée sur la pénalisation par variation totale avec poids. Un premier ensemble de résultats vise à étudier l'intensité sous une hypothèse a priori de segmentation sparse. Dans une seconde partie, nous étudions la technique de binarisation de variables explicatives continues, pour laquelle nous construisons une régularisation spécifique à ce problème. Cette régularisation est intitulée ``binarsity'', elle pénalise les valeurs différentes d'un vecteur de paramètres. Dans la troisième partie, nous nous intéressons à la régression dynamique pour les modèles d'Aalen et de Cox avec coefficients et covariables en grande dimension, et pouvant dépendre du temps. Pour chacune des procédures d'estimation proposées, nous démontrons des inégalités oracles non-asymptotiques en prédiction. Nous utilisons enfin des algorithmes proximaux pour résoudre les problèmes convexes sous-jacents, et nous illustrons nos méthodes sur des données simulées et réelles. / In the first part of this thesis, we deal with the problem of learning the inhomogeneous intensity of a counting process, under a sparse segmentation assumption. We introduce a weighted total-variation penalization, using data-driven weights that correctly scale the penalization along the observation interval. In the second part, we study the binarization technique of continuous features, for which we construct a specific regularization. This regularization is called “binarsity”, it computes the different values of a parameter. In the third part, we are interested in the dynamic regression models of Aalen and Cox with time-varying covariates and coefficients in high-dimensional settings. For each proposed estimation procedure, we give theoretical guaranties by proving non-asymptotic oracle inequalities in prediction. We finally present proximal algorithms to solve the underlying studied convex problems, and we illustrate our methods with simulated and real datasets.
23

Neural Networks for Document Image and Text Processing

Pastor Pellicer, Joan 03 November 2017 (has links)
Nowadays, the main libraries and document archives are investing a considerable effort on digitizing their collections. Indeed, most of them are scanning the documents and publishing the resulting images without their corresponding transcriptions. This seriously limits the document exploitation possibilities. When the transcription is necessary, it is manually performed by human experts, which is a very expensive and error-prone task. Obtaining transcriptions to the level of required quality demands the intervention of human experts to review and correct the resulting output of the recognition engines. To this end, it is extremely useful to provide interactive tools to obtain and edit the transcription. Although text recognition is the final goal, several previous steps (known as preprocessing) are necessary in order to get a fine transcription from a digitized image. Document cleaning, enhancement, and binarization (if they are needed) are the first stages of the recognition pipeline. Historical Handwritten Documents, in addition, show several degradations, stains, ink-trough and other artifacts. Therefore, more sophisticated and elaborate methods are required when dealing with these kind of documents, even expert supervision in some cases is needed. Once images have been cleaned, main zones of the image have to be detected: those that contain text and other parts such as images, decorations, versal letters. Moreover, the relations among them and the final text have to be detected. Those preprocessing steps are critical for the final performance of the system since an error at this point will be propagated during the rest of the transcription process. The ultimate goal of the Document Image Analysis pipeline is to receive the transcription of the text (Optical Character Recognition and Handwritten Text Recognition). During this thesis we aimed to improve the main stages of the recognition pipeline, from the scanned documents as input to the final transcription. We focused our effort on applying Neural Networks and deep learning techniques directly on the document images to extract suitable features that will be used by the different tasks dealt during the following work: Image Cleaning and Enhancement (Document Image Binarization), Layout Extraction, Text Line Extraction, Text Line Normalization and finally decoding (or text line recognition). As one can see, the following work focuses on small improvements through the several Document Image Analysis stages, but also deals with some of the real challenges: historical manuscripts and documents without clear layouts or very degraded documents. Neural Networks are a central topic for the whole work collected in this document. Different convolutional models have been applied for document image cleaning and enhancement. Connectionist models have been used, as well, for text line extraction: first, for detecting interest points and combining them in text segments and, finally, extracting the lines by means of aggregation techniques; and second, for pixel labeling to extract the main body area of the text and then the limits of the lines. For text line preprocessing, i.e., to normalize the text lines before recognizing them, similar models have been used to detect the main body area and then to height-normalize the images giving more importance to the central area of the text. Finally, Convolutional Neural Networks and deep multilayer perceptrons have been combined with hidden Markov models to improve our transcription engine significantly. The suitability of all these approaches has been tested with different corpora for any of the stages dealt, giving competitive results for most of the methodologies presented. / Hoy en día, las principales librerías y archivos está invirtiendo un esfuerzo considerable en la digitalización de sus colecciones. De hecho, la mayoría están escaneando estos documentos y publicando únicamente las imágenes sin transcripciones, limitando seriamente la posibilidad de explotar estos documentos. Cuando la transcripción es necesaria, esta se realiza normalmente por expertos de forma manual, lo cual es una tarea costosa y propensa a errores. Si se utilizan sistemas de reconocimiento automático se necesita la intervención de expertos humanos para revisar y corregir la salida de estos motores de reconocimiento. Por ello, es extremadamente útil para proporcionar herramientas interactivas con el fin de generar y corregir la transcripciones. Aunque el reconocimiento de texto es el objetivo final del Análisis de Documentos, varios pasos previos (preprocesamiento) son necesarios para conseguir una buena transcripción a partir de una imagen digitalizada. La limpieza, mejora y binarización de las imágenes son las primeras etapas del proceso de reconocimiento. Además, los manuscritos históricos tienen una mayor dificultad en el preprocesamiento, puesto que pueden mostrar varios tipos de degradaciones, manchas, tinta a través del papel y demás dificultades. Por lo tanto, este tipo de documentos requiere métodos de preprocesamiento más sofisticados. En algunos casos, incluso, se precisa de la supervisión de expertos para garantizar buenos resultados en esta etapa. Una vez que las imágenes han sido limpiadas, las diferentes zonas de la imagen deben de ser localizadas: texto, gráficos, dibujos, decoraciones, letras versales, etc. Por otra parte, también es importante conocer las relaciones entre estas entidades. Estas etapas del pre-procesamiento son críticas para el rendimiento final del sistema, ya que los errores cometidos en aquí se propagarán al resto del proceso de transcripción. El objetivo principal del trabajo presentado en este documento es mejorar las principales etapas del proceso de reconocimiento completo: desde las imágenes escaneadas hasta la transcripción final. Nuestros esfuerzos se centran en aplicar técnicas de Redes Neuronales (ANNs) y aprendizaje profundo directamente sobre las imágenes de los documentos, con la intención de extraer características adecuadas para las diferentes tareas: Limpieza y Mejora de Documentos, Extracción de Líneas, Normalización de Líneas de Texto y, finalmente, transcripción del texto. Como se puede apreciar, el trabajo se centra en pequeñas mejoras en diferentes etapas del Análisis y Procesamiento de Documentos, pero también trata de abordar tareas más complejas: manuscritos históricos, o documentos que presentan degradaciones. Las ANNs y el aprendizaje profundo son uno de los temas centrales de esta tesis. Diferentes modelos neuronales convolucionales se han desarrollado para la limpieza y mejora de imágenes de documentos. También se han utilizado modelos conexionistas para la extracción de líneas: primero, para detectar puntos de interés y segmentos de texto y, agregarlos para extraer las líneas del documento; y en segundo lugar, etiquetando directamente los píxeles de la imagen para extraer la zona central del texto y así definir los límites de las líneas. Para el preproceso de las líneas de texto, es decir, la normalización del texto antes del reconocimiento final, se han utilizado modelos similares a los mencionados para detectar la zona central del texto. Las imagenes se rescalan a una altura fija dando más importancia a esta zona central. Por último, en cuanto a reconocimiento de escritura manuscrita, se han combinado técnicas de ANNs y aprendizaje profundo con Modelos Ocultos de Markov, mejorando significativamente los resultados obtenidos previamente por nuestro motor de reconocimiento. La idoneidad de todos estos enfoques han sido testeados con diferentes corpus en cada una de las tareas tratadas., obtenie / Avui en dia, les principals llibreries i arxius històrics estan invertint un esforç considerable en la digitalització de les seues col·leccions de documents. De fet, la majoria estan escanejant aquests documents i publicant únicament les imatges sense les seues transcripcions, fet que limita seriosament la possibilitat d'explotació d'aquests documents. Quan la transcripció del text és necessària, normalment aquesta és realitzada per experts de forma manual, la qual cosa és una tasca costosa i pot provocar errors. Si s'utilitzen sistemes de reconeixement automàtic es necessita la intervenció d'experts humans per a revisar i corregir l'eixida d'aquests motors de reconeixement. Per aquest motiu, és extremadament útil proporcionar eines interactives amb la finalitat de generar i corregir les transcripcions generades pels motors de reconeixement. Tot i que el reconeixement del text és l'objectiu final de l'Anàlisi de Documents, diversos passos previs (coneguts com preprocessament) són necessaris per a l'obtenció de transcripcions acurades a partir d'imatges digitalitzades. La neteja, millora i binarització de les imatges (si calen) són les primeres etapes prèvies al reconeixement. A més a més, els manuscrits històrics presenten una major dificultat d'analisi i preprocessament, perquè poden mostrar diversos tipus de degradacions, taques, tinta a través del paper i altres peculiaritats. Per tant, aquest tipus de documents requereixen mètodes de preprocessament més sofisticats. En alguns casos, fins i tot, es precisa de la supervisió d'experts per a garantir bons resultats en aquesta etapa. Una vegada que les imatges han sigut netejades, les diferents zones de la imatge han de ser localitzades: text, gràfics, dibuixos, decoracions, versals, etc. D'altra banda, també és important conéixer les relacions entre aquestes entitats i el text que contenen. Aquestes etapes del preprocessament són crítiques per al rendiment final del sistema, ja que els errors comesos en aquest moment es propagaran a la resta del procés de transcripció. L'objectiu principal del treball que estem presentant és millorar les principals etapes del procés de reconeixement, és a dir, des de les imatges escanejades fins a l'obtenció final de la transcripció del text. Els nostres esforços se centren en aplicar tècniques de Xarxes Neuronals (ANNs) i aprenentatge profund directament sobre les imatges de documents, amb la intenció d'extraure característiques adequades per a les diferents tasques analitzades: neteja i millora de documents, extracció de línies, normalització de línies de text i, finalment, transcripció. Com es pot apreciar, el treball realitzat aplica xicotetes millores en diferents etapes de l'Anàlisi de Documents, però també tracta d'abordar tasques més complexes: manuscrits històrics, o documents que presenten degradacions. Les ANNs i l'aprenentatge profund són un dels temes centrals d'aquesta tesi. Diferents models neuronals convolucionals s'han desenvolupat per a la neteja i millora de les dels documents. També s'han utilitzat models connexionistes per a la tasca d'extracció de línies: primer, per a detectar punts d'interés i segments de text i, agregar-los per a extraure les línies del document; i en segon lloc, etiquetant directament els pixels de la imatge per a extraure la zona central del text i així definir els límits de les línies. Per al preprocés de les línies de text, és a dir, la normalització del text abans del reconeixement final, s'han utilitzat models similars als utilitzats per a l'extracció de línies. Finalment, quant al reconeixement d'escriptura manuscrita, s'han combinat tècniques de ANNs i aprenentatge profund amb Models Ocults de Markov, que han millorat significativament els resultats obtinguts prèviament pel nostre motor de reconeixement. La idoneïtat de tots aquests enfocaments han sigut testejats amb diferents corpus en cadascuna de les tasques tractad / Pastor Pellicer, J. (2017). Neural Networks for Document Image and Text Processing [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90443 / TESIS
24

A Formal View on Training of Weighted Tree Automata by Likelihood-Driven State Splitting and Merging

Dietze, Toni 03 June 2019 (has links)
The use of computers and algorithms to deal with human language, in both spoken and written form, is summarized by the term natural language processing (nlp). Modeling language in a way that is suitable for computers plays an important role in nlp. One idea is to use formalisms from theoretical computer science for that purpose. For example, one can try to find an automaton to capture the valid written sentences of a language. Finding such an automaton by way of examples is called training. In this work, we also consider the structure of sentences by making use of trees. We use weighted tree automata (wta) in order to deal with such tree structures. Those devices assign weights to trees in order to, for example, distinguish between good and bad structures. The well-known expectation-maximization algorithm can be used to train the weights for a wta while the state behavior stays fixed. As a way to adapt the state behavior of a wta, state splitting, i.e. dividing a state into several new states, and state merging, i.e. replacing several states by a single new state, can be used. State splitting, state merging, and the expectation maximization algorithm already were combined into the state splitting and merging algorithm, which was successfully applied in practice. In our work, we formalized this approach in order to show properties of the algorithm. We also examined a new approach – the count-based state merging algorithm – which exclusively relies on state merging. When dealing with trees, another important tool is binarization. A binarization is a strategy to code arbitrary trees by binary trees. For each of three different binarizations we showed that wta together with the binarization are as powerful as weighted unranked tree automata (wuta). We also showed that this is still true if only probabilistic wta and probabilistic wuta are considered.:How to Read This Thesis 1. Introduction 1.1. The Contributions and the Structure of This Work 2. Preliminaries 2.1. Sets, Relations, Functions, Families, and Extrema 2.2. Algebraic Structures 2.3. Formal Languages 3. Language Formalisms 3.1. Context-Free Grammars (CFGs) 3.2. Context-Free Grammars with Latent Annotations (CFG-LAs) 3.3. Weighted Tree Automata (WTAs) 3.4. Equivalences of WCFG-LAs and WTAs 4. Training of WTAs 4.1. Probability Distributions 4.2. Maximum Likelihood Estimation 4.3. Probabilities and WTAs 4.4. The EM Algorithm for WTAs 4.5. Inside and Outside Weights 4.6. Adaption of the Estimation of Corazza and Satta [CS07] to WTAs 5. State Splitting and Merging 5.1. State Splitting and Merging for Weighted Tree Automata 5.1.1. Splitting Weights and Probabilities 5.1.2. Merging Probabilities 5.2. The State Splitting and Merging Algorithm 5.2.1. Finding a Good π-Distributor 5.2.2. Notes About the Berkeley Parser 5.3. Conclusion and Further Research 6. Count-Based State Merging 6.1. Preliminaries 6.2. The Likelihood of the Maximum Likelihood Estimate and Its Behavior While Merging 6.3. The Count-Based State Merging Algorithm 6.3.1. Further Adjustments for Practical Implementations 6.4. Implementation of Count-Based State Merging 6.5. Experiments with Artificial Automata and Corpora 6.5.1. The Artificial Automata 6.5.2. Results 6.6. Experiments with the Penn Treebank 6.7. Comparison to the Approach of Carrasco, Oncina, and Calera-Rubio [COC01] 6.8. Conclusion and Further Research 7. Binarization 7.1. Preliminaries 7.2. Relating WSTAs and WUTAs via Binarizations 7.2.1. Left-Branching Binarization 7.2.2. Right-Branching Binarization 7.2.3. Mixed Binarization 7.3. The Probabilistic Case 7.3.1. Additional Preliminaries About WSAs 7.3.2. Constructing an Out-Probabilistic WSA from a Converging WSA 7.3.3. Binarization and Probabilistic Tree Automata 7.4. Connection to the Training Methods in Previous Chapters 7.5. Conclusion and Further Research A. Proofs for Preliminaries B. Proofs for Training of WTAs C. Proofs for State Splitting and Merging D. Proofs for Count-Based State Merging Bibliography List of Algorithms List of Figures List of Tables Index Table of Variable Names
25

Binary Recurrent Unit: Using FPGA Hardware to Accelerate Inference in Long Short-Term Memory Neural Networks

Mealey, Thomas C. 31 May 2018 (has links)
No description available.
26

Document image analysis of Balinese palm leaf manuscripts / Analyse d'images de documents des manuscrits balinais sur feuilles de palmier

Kesiman, Made Windu Antara 05 July 2018 (has links)
Les collections de manuscrits sur feuilles de palmier sont devenues une partie intégrante de la culture et de la vie des peuples de l'Asie du Sud-Est. Avec l’augmentation des projets de numérisation des documents patrimoniaux à travers le monde, les collections de manuscrits sur feuilles de palmier ont finalement attiré l'attention des chercheurs en analyse d'images de documents (AID). Les travaux de recherche menés dans le cadre de cette thèse ont porté sur les manuscrits d'Indonésie, et en particulier sur les manuscrits de Bali. Nos travaux visent à proposer des méthodes d’analyse pour les manuscrits sur feuilles de palmier. En effet, ces collections offrent de nouveaux défis car elles utilisent, d’une part, un support spécifique : les feuilles de palmier, et d’autre part, un langage et un script qui n'ont jamais été analysés auparavant. Prenant en compte, le contexte et les conditions de stockage des collections de manuscrits sur feuilles de palmier à Bali, nos travaux ont pour objectif d’apporter une valeur ajoutée aux manuscrits numérisés en développant des outils pour analyser, translittérer et indexer le contenu des manuscrits sur feuilles de palmier. Ces systèmes rendront ces manuscrits plus accessibles, lisibles et compréhensibles à un public plus large ainsi que pour les chercheurs et les étudiants du monde entier. Cette thèse a permis de développer un système d’AID pour les images de documents sur feuilles de palmier, comprenant plusieurs tâches de traitement d'images : numérisation du document, construction de la vérité terrain, binarisation, segmentation des lignes de texte et des glyphes, la reconnaissance des glyphes et des mots, translittération et l’indexation de document. Nous avons ainsi créé le premier corpus et jeu de données de manuscrits balinais sur feuilles de palmier. Ce corpus est actuellement disponible pour les chercheurs en AID. Nous avons également développé un système de reconnaissance des glyphes et un système de translittération automatique des manuscrits balinais. Cette thèse propose un schéma complet de reconnaissance de glyphes spatialement catégorisé pour la translittération des manuscrits balinais sur feuilles de palmier. Le schéma proposé comprend six tâches : la segmentation de lignes de texte et de glyphes, un processus de classification de glyphes, la détection de la position spatiale pour la catégorisation des glyphes, une reconnaissance globale et catégorisée des glyphes, la sélection des glyphes et la translittération basée sur des règles phonologiques. La translittération automatique de l'écriture balinaise nécessite de mettre en œuvre des mécanismes de représentation des connaissances et des règles phonologiques. Nous proposons un système de translittération sans segmentation basée sur la méthode LSTM. Celui-ci a été testé sur des données réelles et synthétiques. Il comprend un schéma d'apprentissage à deux niveaux pouvant s’appliquer au niveau du mot et au niveau de la ligne de texte. / The collection of palm leaf manuscripts is an important part of Southeast Asian people’s culture and life. Following the increasing of the digitization projects of heritage documents around the world, the collection of palm leaf manuscripts in Southeast Asia finally attracted the attention of researchers in document image analysis (DIA). The research work conducted for this dissertation focused on the heritage documents of the collection of palm leaf manuscripts from Indonesia, especially the palm leaf manuscripts from Bali. This dissertation took part in exploring DIA researches for palm leaf manuscripts collection. This collection offers new challenges for DIA researches because it uses palm leaf as writing media and also with a language and script that have never been analyzed before. Motivated by the contextual situations and real conditions of the palm leaf manuscript collections in Bali, this research tried to bring added value to digitized palm leaf manuscripts by developing tools to analyze, to transliterate and to index the content of palm leaf manuscripts. These systems aim at making palm leaf manuscripts more accessible, readable and understandable to a wider audience and, to scholars and students all over the world. This research developed a DIA system for document images of palm leaf manuscripts, that includes several image processing tasks, beginning with digitization of the document, ground truth construction, binarization, text line and glyph segmentation, ending with glyph and word recognition, transliteration and document indexing and retrieval. In this research, we created the first corpus and dataset of the Balinese palm leaf manuscripts for the DIA research community. We also developed the glyph recognition system and the automatic transliteration system for the Balinese palm leaf manuscripts. This dissertation proposed a complete scheme of spatially categorized glyph recognition for the transliteration of Balinese palm leaf manuscripts. The proposed scheme consists of six tasks: the text line and glyph segmentation, the glyph ordering process, the detection of the spatial position for glyph category, the global and categorized glyph recognition, the option selection for glyph recognition and the transliteration with phonological rules-based machine. An implementation of knowledge representation and phonological rules for the automatic transliteration of Balinese script on palm leaf manuscript is proposed. The adaptation of a segmentation-free LSTM-based transliteration system with the generated synthetic dataset and the training schemes at two different levels (word level and text line level) is also proposed.
27

Uma metodologia de binarização para áreas de imagens de cheque utilizando algoritmos de aprendizagem supervisionada

Alves, Rafael Félix 23 June 2015 (has links)
Made available in DSpace on 2016-03-15T19:38:02Z (GMT). No. of bitstreams: 1 RAFAEL FELIX ALVES.pdf: 2156088 bytes, checksum: a82e527c69001eb9cee5a989bde3b8dc (MD5) Previous issue date: 2015-06-23 / The process of image binarization consists of transforming a color image into a new one with only two colors: black and white. This process is an important step for many modern applica-tions such as Check Clearance, Optical Character Recognition and Handwriting Recognition. Improvements in the automatic process of image binarization represent impacts on applications that rely on this step. The present work proposes a methodology for automatic image binariza-tion. This methodology applies supervised learning algorithms to binarize images and consists of the following steps: images database construction; extraction of the region of interest; pat-terns matrix construction; pattern labelling; database sampling; and classifier training. Experi-mental results are presented using a database of Brazilian bank check images and the competi-tion database DIBCO 2009. In conclusion, the proposal demonstrated to be superior to some of its competitors in terms of accuracy and F-Measure. / O processo de binarização de imagens consiste na transformação de uma imagem colorida em uma nova imagem com apenas duas cores: uma que representa o fundo, outra o objeto de interesse. Este processo é uma importante etapa de diversas aplicações modernas, como a Compensação de Cheque, o Reconhecimento Ótico de Caracteres (do inglês Optical Characterer Recognition) e o Reconhecimento de Texto Manuscrito (do inglês Handwritten Recognition, HWR). Dado que melhorias no processo automático de binarização de imagens representam impactos diretos nas aplicações que dependem desta etapa o presente trabalho propõe uma metodologia para realizar a binarização automática de imagens. A proposta realiza a binarização de forma automática baseado no uso de algoritmos de aprendizagem supervisionada, tais como redes neurais artificiais e árvore de decisão. O processo como um todo consiste das seguintes etapas: construção do banco de imagens; extração da região de interesse; construção da matriz de padrões; rotulação dos padrões; amostragem da base; e treinamento do classificador. Resultados experimentais são apresentados utilizando uma base de imagens de cheques de bancos brasileiros (CMC-7 e montante de cortesia) e a base de imagens da competição DIBCO 2009. Em conclusão, a metodologia proposta apresentou-se competitiva aos métodos da literatura destacando-se em aplicações onde o processamento de imagens está restrito a uma categoria de imagens, como é o caso das imagens de cheques de bancos brasileiros. A presente metodologia apresenta resultados experimentais entre as três primeiras posições e melhores resultados em relação a medida F-Measure quando comparada com as demais.
28

Implementace neuronové sítě bez operace násobení / Neural Network Implementation without Multiplication

Slouka, Lukáš January 2018 (has links)
The subject of this thesis is neural network acceleration with the goal of reducing the number of floating point multiplications. The theoretical part of the thesis surveys current trends and methods used in the field of neural network acceleration. However, the focus is on the binarization techniques which allow replacing multiplications with logical operators. The theoretical base is put into practice in two ways. First is the GPU implementation of crucial binary operators in the Tensorflow framework with a performance benchmark. Second is an application of these operators in simple image classifier. Results are certainly encouraging. Implemented operators achieve speed-up by a factor of 2.5 when compared to highly optimized cuBLAS operators. The last chapter compares accuracies achieved by binarized models and their full-precision counterparts on various architectures.
29

Dekódování čárového kódu v obraze / Decoding Barcode in Image

Bačíková, Petra January 2011 (has links)
The thesis describes the basic types of barcodes, their development and history. It's mentioned cutting barcodes by dimension, types of barcodes which are the best known and the best used, are described. The key chapter describes details of EAN-8, EAN-13, UPC-A and the additional symbol. It's outlined an algorithm for decoding barcode in image. In conclusion, the results are evaluated and a further development of the project is outlined.
30

Generátor otisků prstů / Fingerprints Generator

Chaloupka, Radek Unknown Date (has links)
Algorithms for fingerprints recognition are already known for long time and there is also an effort for their best optimization. This master's thesis is dealing with an opposite approach, where the fingerprints are not being recognized, but are generated on the minutiae position basis. Such algorithm is then free of the minutiae detection from image and enhancements of fingerprints. Results of this work are the synthetic images generated according to few given parameters, especially minutiae.

Page generated in 0.101 seconds