1,623 research outputs found

    Recognition of License Plates and Optical Nerve Pattern Detection Using Hough Transform

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    The global technique of detection of the features is Hough transform used in image processing, computer vision and image analysis. The detection of prominent line of the object under consideration is the main purpose of the Hough transform which is carried out by the process of voting. The first part of this work is the use of Hough transform as feature vector, tested on Indian license plate system, having font of UK standard and UK standard 3D, which has ten slots for characters and numbers.So tensub images are obtained.These sub images are fed to Hough transform and Hough peaks to extract the Hough peaks information. First two Hough peaks are taken into account for the recognition purposes. The edge detection along with image rotation is also used prior to the implementation of Hough transform in order to get the edges of the gray scale image. Further, the image rotation angle is varied; the superior results are taken under consideration. The second part of this work makes the use of Hough transform and Hough peaks, for examining the optical nerve patterns of eye. An available database for RIM-one is used to serve the purpose. The optical nerve pattern is unique for every human being and remains almost unchanged throughout the life time. So the purpose is to detect the change in the pattern report the abnormality, to make automatic system so capable that they can replace the experts of that field. For this detection purpose Hough Transform and Hough Peaks are used and the fact that these nerve patterns are unique in every sense is confirmed

    Text Line Segmentation of Historical Documents: a Survey

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    There is a huge amount of historical documents in libraries and in various National Archives that have not been exploited electronically. Although automatic reading of complete pages remains, in most cases, a long-term objective, tasks such as word spotting, text/image alignment, authentication and extraction of specific fields are in use today. For all these tasks, a major step is document segmentation into text lines. Because of the low quality and the complexity of these documents (background noise, artifacts due to aging, interfering lines),automatic text line segmentation remains an open research field. The objective of this paper is to present a survey of existing methods, developed during the last decade, and dedicated to documents of historical interest.Comment: 25 pages, submitted version, To appear in International Journal on Document Analysis and Recognition, On line version available at http://www.springerlink.com/content/k2813176280456k3

    Coronal loop detection from solar images and extraction of salient contour groups from cluttered images.

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    This dissertation addresses two different problems: 1) coronal loop detection from solar images: and 2) salient contour group extraction from cluttered images. In the first part, we propose two different solutions to the coronal loop detection problem. The first solution is a block-based coronal loop mining method that detects coronal loops from solar images by dividing the solar image into fixed sized blocks, labeling the blocks as Loop or Non-Loop , extracting features from the labeled blocks, and finally training classifiers to generate learning models that can classify new image blocks. The block-based approach achieves 64% accuracy in IO-fold cross validation experiments. To improve the accuracy and scalability, we propose a contour-based coronal loop detection method that extracts contours from cluttered regions, then labels the contours as Loop and Non-Loop , and extracts geometric features from the labeled contours. The contour-based approach achieves 85% accuracy in IO-fold cross validation experiments, which is a 20% increase compared to the block-based approach. In the second part, we propose a method to extract semi-elliptical open curves from cluttered regions. Our method consists of the following steps: obtaining individual smooth contours along with their saliency measures; then starting from the most salient contour, searching for possible grouping options for each contour; and continuing the grouping until an optimum solution is reached. Our work involved the design and development of a complete system for coronal loop mining in solar images, which required the formulation of new Gestalt perceptual rules and a systematic methodology to select and combine them in a fully automated judicious manner using machine learning techniques that eliminate the need to manually set various weight and threshold values to define an effective cost function. After finding salient contour groups, we close the gaps within the contours in each group and perform B-spline fitting to obtain smooth curves. Our methods were successfully applied on cluttered solar images from TRACE and STEREO/SECCHI to discern coronal loops. Aerial road images were also used to demonstrate the applicability of our grouping techniques to other contour-types in other real applications

    Geological Object Recognition in Extraterrestrial Environments

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    On July 4 1997, the landing of NASA’s Pathnder probe and its rover Sojourner marked the beginning of a new era in space exploration; robots with the ability to move have made up the vanguard of human extraterrestrial exploration ever since. With Sojourners landing, for the rst time, a ground traversing robot was at a distance too far from earth to make direct human control practical. This has given rise to the development of autonomous systems to improve the e?ciency of these robots,in both their ability to move,and their ability to make decisions regarding their environment. Computer Vision comprises a large part of these autonomous systems, and in the course of performing these tasks a large number of images are taken for the purpose of navigation. The limited nature of the current Deep Space Network means that a majority of these images are never seen by human eyes. This work explores the possibility of using these images to target certain features by using a combination of three AdaBoost algorithms and established image feature approaches to help prioritize interesting subjects from an ever growing data set of imaging data

    Automatic Update of Airport GIS by Remote Sensing Image Analysis

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    This project investigates ways to automatically update Geographic Information Systems (GIS) for airports by analysis of Very High Resolution (VHR) remote sensing images. These GIS databases map the physical layout of an airport by representing a broad range of features (such as runways, taxiways and roads) as georeferenced vector objects. Updating such systems therefore involves both automatic detection of relevant objects from remotely sensed images, and comparison of these objects between bi-temporal images. The size of the VHR images and the diversity of the object types to be captured in the GIS databases makes this a very large and complex problem. Therefore we must split it into smaller parts which can be framed as instances of image processing problems. The aim of this project is to apply a range of methodologies to these problems and compare their results, providing quantitative data where possible. In this report, we devote a chapter to each sub-problem that was focussed on. Chapter 1 begins by introducing the background and motivation of the project, and describes the problem in more detail. Chapter 2 presents a method for detecting and segmenting runways, by detecting their distinctive markings and feeding them into a modified Hough transform. The algorithm was tested on a dataset of six bi-temporal remote sensing image pairs and validated against manually generated ground-truth GIS data, provided by Jeppesen. Chapter 3 investigates co-registration of bi-temporal images, as a necessary precursor to most direct change detection algorithms. Chapter 4 then tests a range of bi-temporal change detection algorithms (some standard, some novel) on co-registered images of airports, with the aim of producing a change heat-map which may assist a human operator in rapidly focussing attention on areas that have changed significantly. Chapter 5 explores a number of approaches to detecting curvilinear AMDB features such as taxilines and stopbars, by means of enhancing such features and suppressing others, prior to thresholding. Finally in Chapter 6 we develop a method for distinguishing between AMDB lines and other curvilinear structures that may occur in an image, by analysing the connectivity between such features and the runways

    Segmentation of Football Video Broadcast

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    In this paper a novel segmentation system for football player detection in broadcasted video is presented. Proposed detection system is a complex solution incorporating a dominant color based segmentation technique of a football playfield, a 3D playfield modeling algorithm based on Hough transform and a dedicated algorithm for player tracking, player detection system based on the combination of Histogram of Oriented Gradients (HOG) descriptors with Principal Component Analysis (PCA) and linear Support Vector Machine (SVM) classification. For the shot classification the several classification technique SVM, artificial neural network and Linear Discriminant Analysis (LDA) are used. Evaluation of the system is carried out using HD (1280×720) resolution test material. Additionally, performance of the proposed system is tested with different lighting conditions (including non-uniform pith lightning and multiple player shadows) and various camera positions. Experimental results presented in this paper show that combination of these techniques seems to be a promising solution for locating and segmenting objects in a broadcasted video

    A general approach for multi-oriented text line extraction of handwritten document

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    International audienceThe multi-orientation occurs frequently in ancient handwritten documents, where the writers try to update a document by adding some annotations in the margins. Due to the margin narrowness, this gives rise to lines in different directions and orientations. Document recognition needs to find the lines everywhere they are written whatever their orientation. This is why we propose in this paper a new approach allowing us to extract the multi-oriented lines in scanned documents. Because of the multi-orientation of lines and their dispersion in the page, we use an image meshing allowing us to progressively and locally determine the lines. Once the meshing is established, the orientation is determined using the Wigner-Ville distribution on the projection histogram profile. This local orientation is then enlarged to limit the orientation in the neighborhood. Afterward, the text lines are extracted locally in each zone basing on the follow-up of the orientation lines and the proximity of connected components. Finally, the connected components that overlap and touch in adjacent lines are separated. The morphology analysis of the terminal letters of Arabic words is here considered. The proposed approach has been experimented on 100 documents reaching an accuracy of about 98.6

    Image processing by region extraction using a clustering approach based on color

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    This thesis describes an image segmentation technique based on watersheds, a clustering technique which does not use spatial information, but relies on multispectral images. These are captured using a monochrome camera and narrow-band filters; we call this color segmentation, although it does not use color in a physiological sense. A major part of the work is testing the method developed using different color images. Starting with a general discussion of image processing, the different techniques used in image segmentation are reviewed, and the application of mathematical morphology to image processing is discussed. The use of watersheds as a clustering technique in two- dimensional color space is discussed, and system performance illustrated. The method can be improved for industrial applications by using normalized color to eliminate the problem of shadows. These methods are extended to segment the image into regions recursively. Different types of color images including both man made color images, and natural color images have been used to illustrate performance. There is a brief discussion and a simple illustration showing how segmentation can be used in image compression, and of the application of pyramidal data structures in clustering for coarse segmentation. The thesis concludes with an investigation of the methods which can be used to improve these segmentation results. This includes edge extraction, texture extraction, and recursive merging

    Proof-of-Concept

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    Biometry is an area in great expansion and is considered as possible solution to cases where high authentication parameters are required. Although this area is quite advanced in theoretical terms, using it in practical terms still carries some problems. The systems available still depend on a high cooperation level to achieve acceptable performance levels, which was the backdrop to the development of the following project. By studying the state of the art, we propose the creation of a new and less cooperative biometric system that reaches acceptable performance levels.A constante necessidade de parâmetros mais elevados de segurança, nomeadamente ao nível de autenticação, leva ao estudo biometria como possível solução. Actualmente os mecanismos existentes nesta área tem por base o conhecimento de algo que se sabe ”password” ou algo que se possui ”codigo Pin”. Contudo este tipo de informação é facilmente corrompida ou contornada. Desta forma a biometria é vista como uma solução mais robusta, pois garante que a autenticação seja feita com base em medidas físicas ou compartimentais que definem algo que a pessoa é ou faz (”who you are” ou ”what you do”). Sendo a biometria uma solução bastante promissora na autenticação de indivíduos, é cada vez mais comum o aparecimento de novos sistemas biométricos. Estes sistemas recorrem a medidas físicas ou comportamentais, de forma a possibilitar uma autenticação (reconhecimento) com um grau de certeza bastante considerável. O reconhecimento com base no movimento do corpo humano (gait), feições da face ou padrões estruturais da íris, são alguns exemplos de fontes de informação em que os sistemas actuais se podem basear. Contudo, e apesar de provarem um bom desempenho no papel de agentes de reconhecimento autónomo, ainda estão muito dependentes a nível de cooperação exigida. Tendo isto em conta, e tudo o que já existe no ramo do reconhecimento biometrico, esta área está a dar passos no sentido de tornar os seus métodos o menos cooperativos poss??veis. Possibilitando deste modo alargar os seus objectivos para além da mera autenticação em ambientes controlados, para casos de vigilância e controlo em ambientes não cooperativos (e.g. motins, assaltos, aeroportos). É nesta perspectiva que o seguinte projecto surge. Através do estudo do estado da arte, pretende provar que é possível criar um sistema capaz de agir perante ambientes menos cooperativos, sendo capaz de detectar e reconhecer uma pessoa que se apresente ao seu alcance.O sistema proposto PAIRS (Periocular and Iris Recognition Systema) tal como nome indica, efectua o reconhecimento através de informação extraída da íris e da região periocular (região circundante aos olhos). O sistema é construído com base em quatro etapas: captura de dados, pré-processamento, extração de características e reconhecimento. Na etapa de captura de dados, foi montado um dispositivo de aquisição de imagens com alta resolução com a capacidade de capturar no espectro NIR (Near-Infra-Red). A captura de imagens neste espectro tem como principal linha de conta, o favorecimento do reconhecimento através da íris, visto que a captura de imagens sobre o espectro visível seria mais sensível a variações da luz ambiente. Posteriormente a etapa de pré-processamento implementada, incorpora todos os módulos do sistema responsáveis pela detecção do utilizador, avaliação de qualidade de imagem e segmentação da íris. O modulo de detecção é responsável pelo desencadear de todo o processo, uma vez que esta é responsável pela verificação da exist?ncia de um pessoa em cena. Verificada a sua exist?ncia, são localizadas as regiões de interesse correspondentes ? íris e ao periocular, sendo também verificada a qualidade com que estas foram adquiridas. Concluídas estas etapas, a íris do olho esquerdo é segmentada e normalizada. Posteriormente e com base em vários descritores, é extraída a informação biométrica das regiões de interesse encontradas, e é criado um vector de características biométricas. Por fim, é efectuada a comparação dos dados biometricos recolhidos, com os já armazenados na base de dados, possibilitando a criação de uma lista com os níveis de semelhança em termos biometricos, obtendo assim um resposta final do sistema. Concluída a implementação do sistema, foi adquirido um conjunto de imagens capturadas através do sistema implementado, com a participação de um grupo de voluntários. Este conjunto de imagens permitiu efectuar alguns testes de desempenho, verificar e afinar alguns parâmetros, e proceder a optimização das componentes de extração de características e reconhecimento do sistema. Analisados os resultados foi possível provar que o sistema proposto tem a capacidade de exercer as suas funções perante condições menos cooperativas
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