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Building Detection From Satellite Images Using Shadow And Color InformationGuducu, Hasan Volkan 01 August 2008 (has links) (PDF)
A method for detecting buildings from satellite/aerial images is proposed in this study. The aim is to extract rectilinear buildings by using hypothesize first verify next manner. Hypothesis generation is accomplished by using edge detection and line generation stages. Hypothesis verification is carried out by using
information obtained both from the color segmentation of HSV representation of the image and the shadow detection stages&rsquo / output. Satellite/aerial image is firstly filtered to sharpen the edges. Then, edges are extracted using Canny edge detection
algorithm. These edges are the input for the Hough Transform stage which will produce line segments according to these extracted edges. Then, extracted line segments are used to generate building hypotheses. Verification of these hypotheses
makes use of the outputs of the HSV color segmentation and shadow detection stages. In this study, color segmentation is processed on the HSV representation of the satellite/aerial image which is less sensitive to illumination. In order to perform the shadow detection, the basic information which is shadow areas have higher value of saturation component and lower value of value component in HSV color space is used and according to this information a mask is applied to the HSV
representation of the image to produce shadow pixels.
The proposed method is implemented as software written in MATLAB programming software. The approach was tested in several different areas. The results are encouraging.
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Effect Of Shadow In Building Detection And Building Boundary ExtractionYalcin, Abdurrahman 01 December 2008 (has links) (PDF)
Rectangular-shaped building detection from high resolution aerial/satellite
images is proposed for two different methods. Shadow information plays main role
in both of these algorithms. One of the algorithms is based on Hough
transformation, the other one is based on mean shift segmentation algorithm.
Satellite/aerial images are firstly converted to YIQ color space to be used in shadow
segmentation. Hue and intensity values are used in computing the ratio image which
is used to segment shadowed regions. For shadow segmentation Otsu&rsquo / s method is
used on the histogram of the ratio image. The segmented shadow image is used as
the input for both of two building detection algorithms. In the proposed methods,
shadowed regions are believed to be the building shadows. So, non-shadowed
regions such as roads, cars, trees etc. are discarded before processing the image. In
Hough transform based building detection algorithm, shadowed regions are firstly
segmented one by one and filtered for noise removal and edge sharpening. Then,
the edges in the filtered image are detected by using Canny edge detection
algorithm. Then, line segments are extracted. Finally, the extracted line segments
are used to construct rectangular-shaped buildings. In mean shift based building detection algorithm, image is firstly segmented by using mean shift segmentation
algorithm. By using shadow image and segmented image, building rooftops are
investigated in shadow boundaries. The results are compared for both of the
algorithms. In the last step a shadow removal algorithm is implemented to observe
the effects of shadow regions in both of two implemented building detection
algorithms. Both of these algorithms are applied to shadow removed image and
results are compared.
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Stochastic methods in computational stereoCoffman, Thayne Richard 16 June 2011 (has links)
Computational stereo estimates 3D structure by analyzing visual changes between two or more passive images of a scene that are captured from different viewpoints. It is a key enabler for ubiquitous autonomous systems, large-scale surveying, virtual reality, and improved techniques for compression, tracking, and object recognition. The fact that computational stereo is an under-constrained inverse problem causes many challenges. Its computational and memory requirements are high. Typical heuristics and assumptions, used to constrain solutions or reduce computation, prevent treatment of key realities such as reflection, translucency, ambient lighting changes, or moving objects in the scene. As a result, a general solution is lacking.
Stochastic models are common in computational stereo, but stochastic algorithms are severely under-represented. In this dissertation I present two stochastic algorithms and demonstrate their advantages over deterministic approaches.
I first present the Quality-Efficient Stochastic Sampling (QUESS) approach. QUESS reduces the number of match quality function evaluations needed to estimate dense stereo correspondences. This facilitates the use of complex quality metrics or metrics that take unique values at non-integer disparities. QUESS is shown to outperform two competing approaches, and to have more attractive memory and scaling properties than approaches based on exhaustive sampling.
I then present a second novel approach based on the Hough transform and extend it with distributed ray tracing (DRT). DRT is a stochastic anti-aliasing technique common to computer rendering but which has not been used in computational stereo. I demonstrate that the DRT-enhanced approach outperforms the unenhanced approach, a competing variation that uses re-accumulation in the Hough domain, and another baseline approach. DRT’s advantages are particularly strong for reduced image resolution and/or reduced accumulator matrix resolution. In support of this second approach, I develop two novel variations of the Hough transform that use DRT, and demonstrate that they outperform competing variations on a traditional line segment detection problem.
I generalize these two examples to draw broader conclusions, suggest future work, and call for a deeper exploration by the community. Both practical and academic gaps in the state of the art can be reduced by a renewed exploration of stochastic computational stereo techniques. / text
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Sistema de detecção em tempo real de faixas de sinalização de trânsito para veículos inteligentes utilizando processamento de imagemAlves, Thiago Waszak January 2017 (has links)
A mobilidade é uma marca da nossa civilização. Tanto o transporte de carga quanto o de passageiros compartilham de uma enorme infra-estrutura de conexões operados com o apoio de um sofisticado sistema logístico. Simbiose otimizada de módulos mecânicos e elétricos, os veículos evoluem continuamente com a integração de avanços tecnológicos e são projetados para oferecer o melhor em conforto, segurança, velocidade e economia. As regulamentações organizam o fluxo de transporte rodoviário e as suas interações, estipulando regras a fim de evitar conflitos. Mas a atividade de condução pode tornar-se estressante em diferentes condições, deixando os condutores humanos propensos a erros de julgamento e criando condições de acidente. Os esforços para reduzir acidentes de trânsito variam desde campanhas de re-educação até novas tecnologias. Esses tópicos têm atraído cada vez mais a atenção de pesquisadores e indústrias para Sistemas de Transporte Inteligentes baseados em imagens que visam a prevenção de acidentes e o auxilio ao seu motorista na interpretação das formas de sinalização urbana. Este trabalho apresenta um estudo sobre técnicas de detecção em tempo real de faixas de sinalização de trânsito em ambientes urbanos e intermunicipais, com objetivo de realçar as faixas de sinalização da pista para o condutor do veículo ou veículo autônomo, proporcionando um controle maior da área de tráfego destinada ao veículo e prover alertas de possíveis situações de risco. A principal contribuição deste trabalho é otimizar a formar como as técnicas de processamento de imagem são utilizas para realizar a extração das faixas de sinalização, com o objetivo de reduzir o custo computacional do sistema. Para realizar essa otimização foram definidas pequenas áreas de busca de tamanho fixo e posicionamento dinâmico. Essas áreas de busca vão isolar as regiões da imagem onde as faixas de sinalização estão contidas, reduzindo em até 75% a área total onde são aplicadas as técnicas utilizadas na extração de faixas. Os resultados experimentais mostraram que o algoritmo é robusto em diversas variações de iluminação ambiente, sombras e pavimentos com cores diferentes tanto em ambientes urbanos quanto em rodovias e autoestradas. Os resultados mostram uma taxa de detecção correta média de 98; 1%, com tempo médio de operação de 13,3 ms. / Mobility is an imprint of our civilization. Both freight and passenger transport share a huge infrastructure of connecting links operated with the support of a sophisticated logistic system. As an optimized symbiosis of mechanical and electrical modules, vehicles are evolving continuously with the integration of technological advances and are engineered to offer the best in comfort, safety, speed and economy. Regulations organize the flow of road transportation machines and help on their interactions, stipulating rules to avoid conflicts. But driving can become stressing on different conditions, leaving human drivers prone to misjudgments and creating accident conditions. Efforts to reduce traffic accidents that may cause injuries and even deaths range from re-education campaigns to new technologies. These topics have increasingly attracted the attention of researchers and industries to Image-based Intelligent Transportation Systems that aim to prevent accidents and help your driver in the interpretation of urban signage forms. This work presents a study on real-time detection techniques of traffic signaling signs in urban and intermunicipal environments, aiming at the signaling lanes of the lane for the driver of the vehicle or autonomous vehicle, providing a greater control of the area of traffic destined to the vehicle and to provide alerts of possible risk situations. The main contribution of this work is to optimize how the image processing techniques are used to perform the lanes extraction, in order to reduce the computational cost of the system. To achieve this optimization, small search areas of fixed size and dynamic positioning were defined. These search areas will isolate the regions of the image where the signaling lanes are contained, reducing up to 75% the total area where the techniques used in the extraction of lanes are applied. The experimental results showed that the algorithm is robust in several variations of ambient light, shadows and pavements with different colors, in both urban environments and on highways and motorways. The results show an average detection rate of 98.1%, with average operating time of 13.3 ms.
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Améliorations de la Transformée de Hough en traitement d'images / Enhanced Hough transforms for image processingTu, Chunling 23 September 2014 (has links)
Les travaux effectués dans le cadre de la présente thèse concernent l'analyse et les améliorations apportées à la transformée de Hough Standard (SHT), utilisée en traitement d'image comme simple outil de détection de segments de lignes droites. La transformée de Hough a reçu, depuis sa proposition en 1962, une attention particulière de la part de la communauté. La HT est considérée comme une méthode robuste, dont le principe repose sur la transformation le problème initial de détection de segments de lignes droites en un problème de section de sommets dans l'espace des paramètres, appelé aussi espace HT ou espace de Hough. Les points candidats dans l'espace image sont mis en correspondance points dans l'espace de Hough, en utilisant Le principe avancé par la transformée de Hough est qu'il existe un nombre infini de lignes qui passent par un point, dont la seule différence est l'orientation (l'angle). La transformée de Hough permet de déterminer lesquelles de ces lignes passent au plus près du domaine d'intérêt. Les cellules dans l'espace de Hough échantillonné obtiennent des votes des points candidats. Les maxima locaux, correspondant aux sommets sont construit lorsque les cellules considérées obtiennent plus de votes que les cellules voisines. Les sommets détectés alors dans l'espace des paramètres sont transformée dans l'espace image pour validation. Malheureusement, les opérations les opérations de transformation directe, de l'espace image vers l'espace des paramètres, et inverse engendrent des opérations d'approximation, ce qui est la source de plusieurs problèmes de la transformée de Hough, qui affectent les aspects de robustesse, précision et résolution. On se propose de résoudre ces problèmes dans le cadre des travaux engagés dans le cadre de la thèse. Les contributions, détaillées ci-dessous, ont pu être proposées. A) Pour adresser le problème de limitation en termes de résolution de la SHT, les points concernent la sélection d'une bonne résolution, l'extension de la résolution de la SHT et l'utilisation des techniques de super-résolution pour la HT ont été couverts et de nouvelles propositions ont été faites et qui sont d'une utilité certaine pour les applications de traitement d'image.- la relation entre la performance de la HT et la résolution est proposée, ce qui permet de garantir le bon choix.- Une technique de super-résolution ets proposée en s'appuyant sur le principe de la HT- Une auto-similarité dans les échantillons HT a été découverte et a été utilisée pour obtenir une résolution supérieure de la HT avec un grande fidélité. B) Pour adresser le problème de la précision de la SHT, les erreurs de la HT ont été analysées, lorsque l'on fait subir des transformations géométriques à l'image source. Les erreurs ainsi détectées ont été utilisées pour compenser le manque de précision de la SHT, aboutissant ainsi à une HT plus précise. Afin de permettre l'évaluation de performance des approches proposées dan sel cadre de la thèse, une transformée de Hough idéale est proposée comme référence / The thesis addresses the improvements of the Standard Hough Transform (SHT) for image processing applications. As a common tool for straight line segment detection, the Hough Transform (HT) has received extensive attention since its proposal in 1962. HT is robust since it converts the straight line detection problem to a peak seeking problem in the parameter space (also called HT space or Hough space). Feature points in the image space are mapped to the parameter space, according to the normal formulation of the possible straight lines crossing them. The cells in the digitalised parameter space obtain votes from the feature points. The local maxima, corresponding to peaks are built when corresponding cells obtain more votes than the ones around them. The peaks detected in the parameter space are then mapped back to the image space for validation. Unfortunately, when mapping feature points in the image space to the parameter space in conjunction with the voting process, rounding operations are employed, which leads to several problems of HT. The robustness, accuracy and resolution are all affected. This thesis aims to solve these problems, and the following contributions were made towards this goal : A) Because of the resolution limitation of SHT, the topics of how to select a “good” resolution, how to extend the resolutions of SHT and how to employ the super-resolution technique in HT are covered. In the research of these topics, several outputs are obtained, which are helpful to image processing applications. These include:- The map of HT performance versus resolutions is drawn, according to which “good” choices of resolutions can be found.- HT resolutions are extended by geometrical analysis of the HT butterflies.- Super resolution HT is proposed with consideration to the features of HT.- Self-similarity of the HT butterflies is discovered and employed to obtain high resolution HT with high reliability. B) For the accuracy defect of SHT, the error system of HT is studied when the image is shifted in the image space. The detection errors are employed to compensate for the defect, and an accurate HT is proposed. In order to evaluate existing HT varieties, an ideal HT is proposed as a standard
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Autonomous Quadrotor Navigation by Detecting Vanishing Points in Indoor EnvironmentsJanuary 2018 (has links)
abstract: Toward the ambitious long-term goal of a fleet of cooperating Flexible Autonomous Machines operating in an uncertain Environment (FAME), this thesis addresses various perception and control problems in autonomous aerial robotics. The objective of this thesis is to motivate the use of perspective cues in single images for the planning and control of quadrotors in indoor environments. In addition to providing empirical evidence for the abundance of such cues in indoor environments, the usefulness of these perspective cues is demonstrated by designing a control algorithm for navigating a quadrotor in indoor corridors. An Extended Kalman Filter (EKF), implemented on top of the vision algorithm, serves to improve the robustness of the algorithm to changing illumination.
In this thesis, vanishing points are the perspective cues used to control and navigate a quadrotor in an indoor corridor. Indoor corridors are an abundant source of parallel lines. As a consequence of perspective projection, parallel lines in the real world, that are not parallel to the plane of the camera, intersect at a point in the image. This point is called the vanishing point of the image. The vanishing point is sensitive to the lateral motion of the camera and hence the quadrotor. By tracking the position of the vanishing point in every image frame, the quadrotor can navigate along the center of the corridor.
Experiments are conducted using the Augmented Reality (AR) Drone 2.0. The drone is equipped with the following componenets: (1) 720p forward facing camera for vanishing point detection, (2) 240p downward facing camera, (3) Inertial Measurement Unit (IMU) for attitude control , (4) Ultrasonic sensor for estimating altitude, (5) On-board 1 GHz Processor for processing low level commands. The reliability of the vision algorithm is presented by flying the drone in indoor corridors. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2018
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Análise multiescala de formas planas baseada em estatísticas da transformada de Hough / Multiscale shape analysis based on the Hough transform statisticsRamos, Lucas Alexandre [UNESP] 12 August 2016 (has links)
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Previous issue date: 2016-08-12 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Atualmente, dada a difusão dos computadores, a tarefa de se reconhecer padrões visuais está sendo cada vez mais automatizada, em especial para tratar a vasta e crescente quantidade de imagens digitais existentes. Aplicações de diversas áreas como biometria, recuperação de imagens baseada em conteúdo e diagnóstico médico, se valem do processamento de imagens, bem como de técnicas de extração e análise de características das mesmas, a fim de identificar pessoas, objetos, gestos, textos, etc. As características básicas que são utilizadas para a análise de imagens são: cor, textura e forma. Recentemente, foi proposto um novo descritor de formas denominado HTS (Hough Transform Statistics), o qual se baseia no espaço de Hough para representar e reconhecer objetos em imagens por suas formas. Os resultados obtidos pelo HTS sobre bases de imagens públicas têm mostrado que este novo descritor, além de apresentar altas taxas de acurácia, melhores do que muitos descritores tradicionais propostos na literatura, é rápido, pois tem um algoritmo de complexidade linear. O objetivo deste trabalho foi explorar as possibilidades de representação multiescala do HTS e, assim, propor novos descritores de formas. Escala é um parâmetro essencial em Visão Computacional e a teoria de espaço-escala refere-se ao espaço formado quando se observa, simultaneamente, os aspectos espaciais de uma imagem em várias escalas, sendo a escala a terceira dimensão. Os novos métodos multiescala propostos foram avaliados sobre várias bases de dados e seus desempenhos foram comparados com o desempenho do HTS e com os principais descritores de formas encontrados na literatura. Resultados experimentais mostraram que os novos descritores propostos neste trabalho são mais rápidos e em alguns casos também mais precisos. / Currently, given the widespread of computers through society, the task of recognizing visual patterns is being more and more automated, in particular to treat the large and growing amount of digital images available. Applications in many areas, such as biometrics, content-based image retrieval, and medical diagnostic, make use of image processing, as well as techniques for the extraction and analysis of their characteristics, in order to identify persons, objects, gestures, texts, etc. The basic features that are used for image analysis are: color, texture and shape. Recently, it was proposed a new shape descriptor called HTS (Hough Transform Statistics), which is based on the Hough space to represent and recognize objects in images by their shapes. The results obtained by HTS on public image databases have shown that this new shape descriptor, besides showing high accuracy levels, better than many traditional shape descriptors proposed in the literature, is fast, since it has an algorithm of linear complexity. In this dissertation we explored the possibilities of a multiscale and scale-space representation of this new shape descriptor. Scale is a key parameter in Computer Vision and the theory of scale-space refers to the space formed when observing, simultaneously, special aspects of an image at several scales, being the scale the third dimension. The multiscale HTS methods were evaluated on the same databases and their performances were compared with the main shape descriptors found in the literature and with the monoscale HTS. Experimental results showed that these new descriptors are faster and can also be more accurate in some cases. / FAPESP: 2014/10611-0
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Sistema de detecção em tempo real de faixas de sinalização de trânsito para veículos inteligentes utilizando processamento de imagemAlves, Thiago Waszak January 2017 (has links)
A mobilidade é uma marca da nossa civilização. Tanto o transporte de carga quanto o de passageiros compartilham de uma enorme infra-estrutura de conexões operados com o apoio de um sofisticado sistema logístico. Simbiose otimizada de módulos mecânicos e elétricos, os veículos evoluem continuamente com a integração de avanços tecnológicos e são projetados para oferecer o melhor em conforto, segurança, velocidade e economia. As regulamentações organizam o fluxo de transporte rodoviário e as suas interações, estipulando regras a fim de evitar conflitos. Mas a atividade de condução pode tornar-se estressante em diferentes condições, deixando os condutores humanos propensos a erros de julgamento e criando condições de acidente. Os esforços para reduzir acidentes de trânsito variam desde campanhas de re-educação até novas tecnologias. Esses tópicos têm atraído cada vez mais a atenção de pesquisadores e indústrias para Sistemas de Transporte Inteligentes baseados em imagens que visam a prevenção de acidentes e o auxilio ao seu motorista na interpretação das formas de sinalização urbana. Este trabalho apresenta um estudo sobre técnicas de detecção em tempo real de faixas de sinalização de trânsito em ambientes urbanos e intermunicipais, com objetivo de realçar as faixas de sinalização da pista para o condutor do veículo ou veículo autônomo, proporcionando um controle maior da área de tráfego destinada ao veículo e prover alertas de possíveis situações de risco. A principal contribuição deste trabalho é otimizar a formar como as técnicas de processamento de imagem são utilizas para realizar a extração das faixas de sinalização, com o objetivo de reduzir o custo computacional do sistema. Para realizar essa otimização foram definidas pequenas áreas de busca de tamanho fixo e posicionamento dinâmico. Essas áreas de busca vão isolar as regiões da imagem onde as faixas de sinalização estão contidas, reduzindo em até 75% a área total onde são aplicadas as técnicas utilizadas na extração de faixas. Os resultados experimentais mostraram que o algoritmo é robusto em diversas variações de iluminação ambiente, sombras e pavimentos com cores diferentes tanto em ambientes urbanos quanto em rodovias e autoestradas. Os resultados mostram uma taxa de detecção correta média de 98; 1%, com tempo médio de operação de 13,3 ms. / Mobility is an imprint of our civilization. Both freight and passenger transport share a huge infrastructure of connecting links operated with the support of a sophisticated logistic system. As an optimized symbiosis of mechanical and electrical modules, vehicles are evolving continuously with the integration of technological advances and are engineered to offer the best in comfort, safety, speed and economy. Regulations organize the flow of road transportation machines and help on their interactions, stipulating rules to avoid conflicts. But driving can become stressing on different conditions, leaving human drivers prone to misjudgments and creating accident conditions. Efforts to reduce traffic accidents that may cause injuries and even deaths range from re-education campaigns to new technologies. These topics have increasingly attracted the attention of researchers and industries to Image-based Intelligent Transportation Systems that aim to prevent accidents and help your driver in the interpretation of urban signage forms. This work presents a study on real-time detection techniques of traffic signaling signs in urban and intermunicipal environments, aiming at the signaling lanes of the lane for the driver of the vehicle or autonomous vehicle, providing a greater control of the area of traffic destined to the vehicle and to provide alerts of possible risk situations. The main contribution of this work is to optimize how the image processing techniques are used to perform the lanes extraction, in order to reduce the computational cost of the system. To achieve this optimization, small search areas of fixed size and dynamic positioning were defined. These search areas will isolate the regions of the image where the signaling lanes are contained, reducing up to 75% the total area where the techniques used in the extraction of lanes are applied. The experimental results showed that the algorithm is robust in several variations of ambient light, shadows and pavements with different colors, in both urban environments and on highways and motorways. The results show an average detection rate of 98.1%, with average operating time of 13.3 ms.
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Método de detecção automática de eixos de caminhões baseado em imagens / Truck axle detection automatic method based on imagesNatália Ribeiro Panice 13 September 2018 (has links)
A presente pesquisa tem por objetivo desenvolver um sistema automático de detecção de eixos de caminhões a partir de imagens. Para isso, são apresentados dois sistemas automáticos: o primeiro para extração de imagens de caminhões a partir de filmagens de tráfego rodoviário feitas em seis locais de uma mesma rodovia situada no Estado de São Paulo, e o segundo, para detecção dos eixos dos caminhões nas imagens. Ambos os sistemas foram fundamentados em conceitos de Processamento de Imagens e Visão Computacional e o desenvolvimento foi feito utilizando programação em linguagem Python e as bibliotecas OpenCV e SciKit. O salvamento automático das imagens de caminhões foi necessário para a construção do banco de imagens utilizado no outro método: a detecção dos eixos dos veículos identificados. Neste estágio foram realizadas a segmentação da imagem do caminhão, a detecção propriamente dita e a classificação dos eixos. Na segmentação dos veículos, utilizou-se as técnicas de limiarização adaptativa seguida de morfologia matemática e em outra ocasião, o descritor de texturas LBP; enquanto na detecção, a Transformada de Hough. Da análise de desempenho desses métodos, a taxa de salvamento das imagens foi 69,2% considerando todos os caminhões que se enquadraram nos frames. Com relação às detecções, a segmentação das imagens dos caminhões feita utilizando limiarização adaptativa com morfologia matemática ofereceu resultados de 57,7% da detecção do total de eixos dos caminhões e 65,6% de falsas detecções. A técnica LBP forneceu, para os mesmos casos, respectivamente, 68,3% e 84,2%. O excesso de detecção foi um ponto negativo dos resultados e pode ser relacionado aos problemas do ambiente externo, geralmente intrínsecos às cenas de tráfego de veículos. Dois fatores que interferiram de maneira significativa foram a iluminação e a movimentação das folhas e galhos das árvores devido ao vento. Desconsiderando esse inconveniente, derivado dos fatores recém citados, as taxas de acerto dos dois tipos de segmentação aumentariam para 90,4% e 93,5%, respectivamente, e as falsas detecções mudariam para 66,5% e 54,7%. Desse modo, os dois sistemas propostos podem ser considerados promissores para o objetivo proposto. / This research aims to develop an automatic truck axle detection system using images. Two automatic systems are presented: one for the extraction of truck images from road videos recorded in a São Paulo state highway and one for the axle detection on images. Both systems are based on Image Processing and Computational Vision techniques, with using programming in Python and OpenCV and SciKit libraries. The truck image extraction system was necessary for the creation of image base, to be used on the axle detection system. Thereunto, image segmentation, axle detection and classification on images were made. In segmentation was used adaptive threshold technique, followed by mathematical morphology and on another time, LBP texture descriptors; for detection, was used Hough Transform. Performance analysis on these methods wielded 69.2% on image save rate, on trucks entirely framed on the image. About axle detection, the truck image segmentation using a combination of adaptive threshold and mathematical morphology wielded 57.7% on axle detection, whilst achieving 65.6% of false detection. Using LBP wielded, on the same images, 68.3% on axle detection and 84.2% of false detection. These excesses was a negative result and can be related to intrinsic issues on the external road traffic environment. Two main factors affected the result: lighting condition changes and the movement of tree leaves and branches. Disregarding these two factors, the proposed system had 90.4% axle truck detection rate using adaptive threshold and mathematical morphology and 93.5% using LBP, and the false detection, changed for 66.5% e 54.7%. Thus, both proposed systems are considered promising.
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Runway detection in LWIR video : Real time image processing and presentation of sensor dataCedernaes, Erasmus January 2016 (has links)
Runway detection in long wavelength infrared (LWIR) video could potentially increase the number of successful landings by increasing the situational awareness of pilots and verifying a correct approach. A method for detecting runways in LWIR video was therefore proposed and evaluated for robustness, speed and FPGA acceleration. The proposed algorithm improves the detection probability by making assumptions of the runway appearance during approach, as well as by using a modified Hough line transform and a symmetric search of peaks in the accumulator that is returned by the Hough line transform. A video chain was implemented on a Xilinx ZC702 Development card with input and output via HDMI through an expansion card. The video frames were buffered to RAM, and the detection algorithm ran on the CPU, which however did not meet the real-time requirement. Strategies were proposed that would improve the processing speed by either acceleration in hardware or algorithmic changes.
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