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  • 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.
41

Istar : um esquema estrela otimizado para Image Data Warehouses baseado em similaridade

Anibal, Luana Peixoto 26 August 2011 (has links)
Made available in DSpace on 2016-06-02T19:05:54Z (GMT). No. of bitstreams: 1 3993.pdf: 3294402 bytes, checksum: 982c043143364db53c8a4e2084205995 (MD5) Previous issue date: 2011-08-26 / A data warehousing environment supports the decision-making process through the investigation and analysis of data in an organized and agile way. However, the current data warehousing technologies do not allow that the decision-making processe be carried out based on images pictorial (intrinsic) features. This analysis can not be carried out in a conventional data warehousing because it requires the management of data related to the intrinsic features of the images to perform similarity comparisons. In this work, we propose a new data warehousing environment called iCube to enable the processing of OLAP perceptual similarity queries over images, based on their pictorial (intrinsic) features. Our approach deals with and extends the three main phases of the traditional data warehousing process to allow the use of images as data. For the data integration phase, or ETL phase, we propose a process to represent the image by its intrinsic content (such as color or texture numerical descriptors) and integrate this data with conventional data in the DW. For the dimensional modeling phase, we propose a star schema, called iStar, that stores both the intrinsic and the conventional image data. Moreover, at this stage, our approach models the schema to represent and support the use of different user-defined perceptual layers. For the data analysis phase, we propose an environment in which the OLAP engine uses the image similarity as a query predicate. This environment employs a filter mechanism to speed-up the query execution. The iStar was validated through performance tests for evaluating both the building cost and the cost to process IOLAP queries. The results showed that our approach provided an impressive performance improvement in IOLAP query processing. The performance gain of the iCube over the best related work (i.e. SingleOnion) was up to 98,21%. / Um ambiente de data warehousing (DWing) auxilia seus usuários a tomarem decisões a partir de investigações e análises dos dados de maneira organizada e ágil. Entretanto, os atuais recursos de DWing não possibilitam que o processo de tomada de decisão seja realizado com base em comparações do conteúdo intrínseco de imagens. Esta análise não pode ser realizada por aplicações de DW convencionais porque essa utiliza, como base, imagens digitais e necessita realizar operações baseadas em similaridade, para as quais um DW convencional não oferece suporte. Neste trabalho, é proposto um ambiente de data warehouse chamado iCube que provê suporte ao processamento de consultas IOLAP (Image On-Line Analytical Processing) baseadas em diversas percepções de similaridade entre as imagens. O iCube realiza adaptações nas três principais fases de um ambiente de data warehousing convencional para permitir o uso de imagens como dados de um data warehouse (DW). Para a fase de integração, ou fase ETL (Extract, Trasnform and Load), nós propomos um processo para representar as imagens a partir de seu conteúdo intrínseco (i.e., por exemplo por meio de descritores numéricos que representam cor ou textura dessas imagens) e integrar esse conteúdo intrínseco a dados convencionais em um DW. Neste trabalho, nós também propomos um esquema estrela otimizado para o iCube, denominado iStar, que armazena tanto dados convencionais quanto dados de representação do conteúdo intrínseco das imagens. Ademais, nesta fase, o iStar foi projetado para representar e prover suporte ao uso de diferentes camadas perceptuais definidas pelo usuário. Para a fase de análise de dados, o iCube permite que processos OLAP sejam executados com o uso de comparações de similaridade como predicado de consultas e com o uso de mecanismos de filtragem para acelerar o processamento de consultas OLAP. O iCube foi validado a partir de testes de desempenho para a construção da estrutura e para o processamento de consultas IOLAP. Os resultados demonstraram que o iCube melhora significativamente o desempenho no processamento de consultas IOLAP quando comparado aos atuais recursos de IDWing. Os ganhos de desempenho do iCube contra o melhor trabalho correlato (i.e. SingleOnion) foram de até 98,21%.
42

Novel image processing algorithms and methods for improving their robustness and operational performance

Romanenko, Ilya January 2014 (has links)
Image processing algorithms have developed rapidly in recent years. Imaging functions are becoming more common in electronic devices, demanding better image quality, and more robust image capture in challenging conditions. Increasingly more complicated algorithms are being developed in order to achieve better signal to noise characteristics, more accurate colours, and wider dynamic range, in order to approach the human visual system performance levels.
43

Rozpoznávání textu z obrazových dat / Optical character recognition from image data

Marinič, Michal January 2014 (has links)
The thesis is concerned with optical character recognition from image data with different methods used for character classification. In the first theoretical part it focuses on explanation of all important parts of system for optical character recognition. The latter practical part of the thesis describes an example of image segmentation, the implementation of artificial neural networks for image recognition and create simple training set of data for the evaluation of the network. It also describes the process of training Tesseract tool and its implementation in a simple application EasyTessOCR for character recognition.
44

New Approaches in Airborne Thermal Image Processing for Landscape Assessment / New Approaches in Airborne Thermal Image Processing for Landscape Assessment

Pivovarník, Marek January 2017 (has links)
Letecká termální hyperspektrální data přinášejí řadu informací o teplotě a emisivitě zemského povrchu. Při odhadování těchto parametrů z dálkového snímání tepelného záření je třeba řešit nedourčený systém rovnic. Bylo navrhnuto několik přístupů jak tento problém vyřešit, přičemž nejrozšířenější je algoritmus označovaný jako Temperature and Emissivity Separation (TES). Tato práce má dva hlavní cíle: 1) zlepšení algoritmu TES a 2) jeho implementaci do procesingového řetězce pro zpracování obrazových dat získaných senzorem TASI. Zlepšení algoritmu TES je možné dosáhnout nahrazením používaného modulu normalizování emisivity (tzv. Normalized Emissivity Module) částí, která je založena na vyhlazení spektrálních charakteristik nasnímané radiance. Nový modul je pak označen jako Optimized Smoothing for Temperature Emissivity Separation (OSTES). Algoritmus OSTES je připojen k procesingovému řetězci pro zpracování obrazových dat ze senzoru TASI. Testování na simulovaných datech ukázalo, že použití algoritmu OSTES vede k přesnějším odhadům teploty a emisivity. OSTES byl dále testován na datech získaných ze senzorů ASTER a TASI. V těchto případech však není možné pozorovat výrazné zlepšení z důvodu nedokonalých atmosférických korekcí. Nicméně hodnoty emisivity získané algoritmem OSTES vykazují více homogenní vlastnosti než hodnoty ze standardního produktu senzoru ASTER.
45

Unární klasifikátor obrazových dat / Unary Classification of Image Data

Beneš, Jiří January 2021 (has links)
The work deals with an introduction to classification algorithms. It then divides classifiers into unary, binary and multi-class and describes the different types of classifiers. The work compares individual classifiers and their areas of use. For unary classifiers, practical examples and a list of used architectures are given in the work. The work contains a chapter focused on the comparison of the effects of hyperparameters on the quality of unary classification for individual architectures. Part of the submission is a practical example of implementation of the unary classifier.
46

Einführung in die Digitale Bildverarbeitung: Lehrbuch für ingenieurwissenschaftliche Studiengänge

Richter, Christiane, Teichert, Bernd 07 February 2024 (has links)
Das Buch gibt eine Einführung in die Digitale Bildverarbeitung. Der Inhalt des Buches gliedert sich in sechs Kapitel. Im ersten Kapitel werden die wichtigsten Definitionen und Anwendungsgebiete der Digitalen Bildverarbeitung sowie wesentliche Komponenten eines digitalen Bildverarbeitungssystems erklärt. Das zweite Kapitel befasst sich mit den Grundlagen digitaler Bilder, den Bilddatenformaten und Kompressionsverfahren. Die Grundlagen der Farbtheorie und ein kurzer Überblick über die wichtigsten Farbsysteme werden im dritten Kapitel vermittelt. Die zwei anschließenden Kapitel beschäftigen sich mit der Manipulation von Grauwerten. Der Schwerpunkt liegt hier auf den Punktoperationen und den Filtertechniken. Das letzte Kapitel behandelt die für die Lehrgebiete Photogrammetrie, Fernerkundung und Geoinformationssysteme überaus wichtigen Grundlagen der geometrischen Transformation.:Vorwort 1. Einführung in die digitale Bildverarbeitung 1.1 Definition der Bildverarbeitung 1.2 Anwendungsgebiete der Digitalen Bildverarbeitung 1.3 Komponenten eines Bildverarbeitungssystems 2. Digitale Bilder 2.1 Entstehung digitaler Bilder 2.2 Bildmatrix und Grauwerte 2.3 Digitale Bilder im Ortsbereich 2.3.1 Bildrepräsentation 2.3.2 Auflösung eines Pixels 2.3.3 Das Pixelkoordinatensystem 2.3.4 Grundsätzliche Festlegungen 2.3.5 Topologien oder Nachbarschaftsrelationen 2.3.6 Distanzen 2.4 Eigenschaften digitaler Bilder 2.4.1 Mittelwert und mittlere quadratische Abweichung 2.4.2 Varianz und Standardabweichung 2.4.3 Histogramm 2.4.4 Stochastische Einflüsse 2.5 Kompressionen und Datenformate 2.5.1 Ausgewählte Verfahren zur Bildkompression 2.5.2 Bilddatenformate 3. Farbtheorie 3.1 Was ist Farbe? 3.2 Farbsysteme 3.2.1 RGB- und CMY- Farbsystem 3.2.2 Das Farbdreieck (Maxwell’sches Dreieck) 3.2.3 Das IHS- Modell 3.2.4 Das CIE- Farbmodell 3.3 Bildwiedergabe 3.4 Farbmanipulation 4. Punktoperationen 4.1 Schwellwertoperation zur Erzeugung von Binärbildern 4.2 Arithmetische Bildoperationen 4.3 Logische oder Boolesche Kombinationen 4.4 Kontrast- und Helligkeitsänderungen 4.4.1 Kontrastübertragungsfunktionen 4.4.2 Kontrastveränderung durch Histogrammanpassungen 4.4.3 Äquidensitenherstellung 5. Filteroperationen 5.1 Lineare Filter 5.1.1 Tiefpassfilter 5.1.2 Hochpassfilter 5.1.2.5 Schärfung 5.2 Morphologische Filter 5.2.1 Medianfilter 5.2.2 Minimum- und Maximumfilter 5.2.3 Dilatation und Erosion im Binärbild 5.2.4 Opening und Closing 6. Geometrische Bildtransformationen 6.1 Koordinatentransformationen im 2D-Raum 6.2 Direkte und indirekte Transformation 6.2.1 Direkte Transformation 6.2.2 Indirekte Transformation 6.3 Resampling 6.3.1 Nächster Nachbar 6.3.2 Bilineare Interpolation 6.3.3 Interpolationen höherer Ordnung 6.3.4 Zusammenfassung der Interpolationsmethoden Quellennachweis Sachregister / The book provides an introduction into digital image processing. The content of the book is divided into six chapters. In the first chapter, the most important definitions and areas of application of digital image processing as well as essential components of a digital image processing system are explained. The second chapter deals with the basics of digital images, image data formats and compression methods. The basics of color theory and a brief overview of the most important color systems are presented in the third chapter. The following two chapters deal with the manipulation of gray values. The focus here is on point operations and filtering techniques. The last chapter deals with the fundamentals of geometric transformation, which are extremely important for the areas of photogrammetry, remote sensing and geographic information systems.:Vorwort 1. Einführung in die digitale Bildverarbeitung 1.1 Definition der Bildverarbeitung 1.2 Anwendungsgebiete der Digitalen Bildverarbeitung 1.3 Komponenten eines Bildverarbeitungssystems 2. Digitale Bilder 2.1 Entstehung digitaler Bilder 2.2 Bildmatrix und Grauwerte 2.3 Digitale Bilder im Ortsbereich 2.3.1 Bildrepräsentation 2.3.2 Auflösung eines Pixels 2.3.3 Das Pixelkoordinatensystem 2.3.4 Grundsätzliche Festlegungen 2.3.5 Topologien oder Nachbarschaftsrelationen 2.3.6 Distanzen 2.4 Eigenschaften digitaler Bilder 2.4.1 Mittelwert und mittlere quadratische Abweichung 2.4.2 Varianz und Standardabweichung 2.4.3 Histogramm 2.4.4 Stochastische Einflüsse 2.5 Kompressionen und Datenformate 2.5.1 Ausgewählte Verfahren zur Bildkompression 2.5.2 Bilddatenformate 3. Farbtheorie 3.1 Was ist Farbe? 3.2 Farbsysteme 3.2.1 RGB- und CMY- Farbsystem 3.2.2 Das Farbdreieck (Maxwell’sches Dreieck) 3.2.3 Das IHS- Modell 3.2.4 Das CIE- Farbmodell 3.3 Bildwiedergabe 3.4 Farbmanipulation 4. Punktoperationen 4.1 Schwellwertoperation zur Erzeugung von Binärbildern 4.2 Arithmetische Bildoperationen 4.3 Logische oder Boolesche Kombinationen 4.4 Kontrast- und Helligkeitsänderungen 4.4.1 Kontrastübertragungsfunktionen 4.4.2 Kontrastveränderung durch Histogrammanpassungen 4.4.3 Äquidensitenherstellung 5. Filteroperationen 5.1 Lineare Filter 5.1.1 Tiefpassfilter 5.1.2 Hochpassfilter 5.1.2.5 Schärfung 5.2 Morphologische Filter 5.2.1 Medianfilter 5.2.2 Minimum- und Maximumfilter 5.2.3 Dilatation und Erosion im Binärbild 5.2.4 Opening und Closing 6. Geometrische Bildtransformationen 6.1 Koordinatentransformationen im 2D-Raum 6.2 Direkte und indirekte Transformation 6.2.1 Direkte Transformation 6.2.2 Indirekte Transformation 6.3 Resampling 6.3.1 Nächster Nachbar 6.3.2 Bilineare Interpolation 6.3.3 Interpolationen höherer Ordnung 6.3.4 Zusammenfassung der Interpolationsmethoden Quellennachweis Sachregister
47

Adaptive Waveletmethoden zur Approximation von Bildern / Adaptive wavelet methods for the approximation of images

Tenorth, Stefanie 08 July 2011 (has links)
No description available.
48

Využití obrazové spektroskopie pro monitoring zátěže vegetace polutanty obsaženými v půdním substrátu Sokolovské hnědouhelné pánve / Application of imaging spectroscopy in monitoring of vegetation stress caused by soil pollutants in the Sokolov lignite basin

Mišurec, Jan January 2018 (has links)
Forests can be considered as one of the most important Earth's ecosystems not only because of oxygen production and carbon sequestration via photosynthesis, but also as a source of many natural resources (such as wood) and as a habitat of many specific plants and animals. Monitoring of forest health status is thus crucial activity for keeping all production and ecosystem functions of forests. The main aim of the thesis is development of an alternative approach for forest health status based on airborne hyperspectral data (HyMap) analysis supported by field sampling. The proposed approach tries to use similar vegetation parameters which are used in case of the current methods of forest health status assessment based on field inspections. It is believed that importance of such new methods will significantly increase in the time when the planned satellite hyperspectral missions (e.g. EnMap) will move into operational phase. The developed forest health monitoring approach is practically demonstrated on mature Norway spruce (Picea abies L. Karst) forests of the Sokolov lignite basin which were affected by long-term coal mining and heavy industry and therefore high variability of forest health status was assumed in this case. Two leaf level radiative transfer models were used for simulating spectral...

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