Martian clouds and dust play an important part of the radiative transfer and energy balance budget. To assist in fully understanding the impact of clouds and dust, the complete diurnal cycle needs to be characterized. One of the best methods to track diurnal variations on Mars is by measuring optical depth. The spatial and temporal trends of optical depth give insight into the dust and water cycles of the Martian atmosphere. Until now, spacecraft could only obtain optical depth during the day. In this thesis, nighttime images from the Mars Exploration Rover Spirit are used to calculate nighttime optical depth using photometric methods to capture star flux. Bright stars in well-known constellations are used in this analysis. The observed flux was compared to the expected flux to give nighttime optical depth values. The observed nighttime optical depth was consistently similar to the daytime optical depth values on both an individual image and sol-averaged basis. Recommendations are made going forward to use the Mars Science Laboratory Curiosity for conducting an optimal nighttime optical depth campaign to fully characterize the diurnal dust and water cycles of Mars. The Curiosity rover is well suited for nighttime imaging and can potentially provide valuable insight into the nighttime dust and cloud trends.

Cette thèse propose une méthodologie pour construire un système de reconstruction spatiale et temporelle à partir de plusieurs caméras: étalonnage des caméras et reconstruction 3-D éparse, reconstruction 3-D dense, reconstruction temporelle éparse et dense. Tout d'abord, une formulation probabiliste est dévelo-ppée en association avec des algorithmes de factorisation affine (méthode de reconstruction 3-D fondée sur la factorisation matricielle). Elle permet de récupérer à la fois les paramètres extrinsèques des caméras et les coordonnées 3-D des points de contrôle, étant données les correspondances 2-D de leurs projections et les paramètres intrinsèques des caméras. Le cadre proposé est robuste au bruit et se compare favorablement avec l'ajustement de faisceaux, une méthode standard de minimisation non-linéaire, qui exige un bon estimé initial non loin de l'optimum. Deuxièmement, une méthode d'évolution de maillages est proposée. Elle est capable de gérer les changements topologiques et les auto-intersections sans imposer de contraintes d'échantillonnage sur le maillage. La géométrie exacte du maillage est préservée, à l'exception des parties qui s'auto-intersectent, que l'on retriangularise localement. Des applications sont présentées: le morphing des maillages et la reconstruction 3-D à partir de plusieurs caméras en utilisant des méthodes variationnelles. Troisièmement, une méthode de regroupement de caméras qui utilise l'information de la scène est développée, capable de séparer des reconstructions à grande échelle qui consomment beaucoup de mémoire en plusieurs petites tâches indépendantes de reconstructions partielles utilisant moins de ressources. Enfin, un nouveau descripteur en 3 dimensions est proposé, défini sur des maillages triangulaires échantillonné uniformément. Il est invariant à la rotation, la translation, l'échelle, étant en mesure de capturer les informations géométriques et photométriques locales. Il est particulièrement utile dans le cadre multi-caméras, où les maillages reconstruits bénéficient de la couleur / texture. De plus, le descripteur est défini d'une manière générique pour une fonction quelconque tout au long de la surface (i.e. la couleur, la courbure). Des résultats de correspondance rigide et non rigide sont présentés. Finalement, le descripteur est intégré dans un cadre de suivi temporel dense du maillage.

To reduce cost, many digital cameras use a single sensor array instead of using three arrays for the red, green and blue. Thus at each pixel location only the red, green or blue intensity value is available. And to generate a complete color image, the camera must estimate the missing two values at each pixel location .Color filter arrays are used to capture only one portion of the spectrum (Red, Green or Blue) at each location. Various arrangements of the Color Filter Array (CFA) are possible, but the Bayer array is the most commonly used arrangement and we will deal exclusively with the Bayer array in this thesis. Since each of the three colors channels are effectively downsampled, it leads to aliasing artifacts. This thesis will analyze the effects of aliasing in the frequency- domain and present a method to reduce the deterioration in image quality due to aliasing artifacts. Two reference algorithms, AH-POCS (Adams and Hamilton - Projection Onto Convex Sets) and Adaptive Homogeneity-Directed interpolation, are discussed in de- tail. Both algorithms use the assumption that there is high correlation in the high- frequency regions to reduce aliasing. AH-POCS uses alias cancellation technique to reduce aliasing in the red and blue images, while the Adaptive Homogeneity-Directed interpolation algorithm is an edge-directed algorithm. We present here an algorithm that combines these two techniques and provides a better result on average when compared to the reference algorithms.

Τα ασύρματα δίκτυα αισθητήρων (WSNs) είναι πολύ αναγνωρισμένα στις μέρες μας και γύρω από αυτά έχουν αναπτυχθεί χιλιάδες εφαρμογές που με χρήση άλλης τεχνολογίας ήταν σχεδόν ακατόρθωτες. Ένα WSN αποτελείται από κόμβους οι οποίοι είναι προγραμματισμένοι να επικοινωνούν και να συλλέγουν πληροφορίες μέσω των αισθητήρων που είναι αναρτημένοι πάνω τους. Οι πληροφορίες ή σύνολο των πληροφοριών καταλήγουν τελικά στους κόμβους που είναι προγραμματισμένοι ως τερματικοί κόμβοι ή βάσεις. Οι βάσεις είναι συνήθως συνδεδεμένες με ένα υπολογιστή και μεταφέρουν τα δεδομένα του δικτύου σε αυτόν. Τα κύρια χαρακτηριστικά των ασύρματων δικτύων αισθητήρων είναι η χαμηλή κατανάλωση ενεργείας των συσκευών-κόμβων (motes), η σταθερότητα και η απλότητα του κώδικα καθώς και η μεγάλη αξιοπιστία. Μερικές εφαρμογές των WSNs είναι για παράδειγμα η μέτρηση της υγρασίας στον τάπητα ενός γηπέδου γκολφ, η παρακολούθηση των κρίσιμων μεγεθών σε μεγάλες κατασκευές (π.χ. οι τάσεις των νημάτων μιας κρεμμαστης γέφυρας ή η παρακολούθηση της καταπόνησης των δοκών ενός ουρανοξύστη). Στα πλαίσια της διπλωματικής εργασίας αυτής παρουσιάζουμε ένα ασύρματο δίκτυο αισθητήρων όπου οι αισθητήρες είναι έξυπνες κάμερες! Παρουσιάζει μεγάλο ενδιαφέρον η μελέτη ενός τέτοιου δικτύου καθώς και η ανάπτυξη εφαρμογών γύρω από αυτό. / Wireless Sensor Networks (WSNs) are very much recognized these days, and thousands of applications have been developed in relation to them, which, would have been impossible if other technologies were used. A WSN is made up of nodes programmed to collect information through sensors attached to them and transmit them. The information ends up finally to the nodes which are programmed as terminal nodes or base-stations. These base-stations are usually connected to a computer and transfer the data that have been retrieved from the network to it. The main features of a WSN is the low energy consumption by the node equipment (motes), the stability and simplicity of the code as well as their great reliability. Some applications of the WSNs are, for example, the measurement of humidity in a golf course, the monitoring of the crucial sizes in great constructions (e.g. the tensions of the fibers in a suspension bridge, the monitoring of the strains of girders in a skyscraper) Within the context of this thesis, we present a WSN where the sensors are smart cameras! The study of such a network presents great interest as well as the development of applications based on it.

Over the past century, populations of North American grassland songbirds have declined sharply as a consequence of habitat destruction. Alberta’s mixed-grass prairie constitutes Canada’s largest remaining tract of native grassland. However, this region has recently undergone a rapid expansion of conventional oil and natural gas development, and few studies have documented its effects on songbird nesting success. During the 2012-2014 breeding seasons, I monitored 813 nests of grassland songbirds located at sites that varied with respect to presence/absence, distance from, and types of oil and gas infrastructure (pump jacks, screw pumps, compressor stations) and gravel roads. Nest survival was significantly lower at infrastructure sites relative to controls for both Savannah sparrow and vesper sparrow. Additionally, vesper sparrow nest density was greater within 100 m of structures. These findings suggest that habitat disturbance caused by infrastructure may result in increased frequencies of nest predation at multiple spatial scales. / February 2016

This work aims to present a system for parking spaces detection using opportunistic cameras. The central idea is to use images from cameras that are already installed to identify possible parking spaces. It is important to highlight that legal, privacy and security issues in using cameras for parking detection is out of scope. This work addressed the problem of how to use cameras opportunistically to detect free parking spaces. The idea for the solution is that by means of embedded systems, adapted them to the cameras already installed in the city, we can successfully design the detection of vacancies. The main objective of this work is to present the feasibility of using embedded systems to detect parking spaces, for such, it is proposed three image processing techniques to solve the problem and as main contribution it is presented a distributed architecture for use of cameras opportunistically to obtain the images. The major contributions of this work were the development of three image processing techniques for vehicle detection; a distributed and opportunistic architecture proposal using cameras to detect parking spaces; comparative evaluation of the proposed architecture and two other existing architectures; a routing algorithm for routing requests in the Embedded architecture Initially, it was evaluated three proposed image processing techniques to detect parking spaces, the best technique was the Dilation after Border Detection with a success rate close to 100%, this evaluation was performed to choose the technique used in the rest of this work. After choose the best technique, it was performed an experiment using the proposed architecture and two others that are used for comparison, the result of the experiment demonstrated the feasibility of use the Embedded architecture. To conduct large experiments is a complex task, because of this a simulation was developed using the network simulator Sinalgo to analyze four variables in the system (communication radius, number of auxiliary cameras, amount of simultaneous requests and percentage of failed cameras). The simulation result shows that the factors with the greatest influence on the variation of the average times of the requests are the size of the communication radius and the amount of auxiliary cameras. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho apresenta um sistema para detecção de vagas de estacionamento utilizando câmeras de forma oportunista. A ideia central é a utilização de imagens provenientes de câmeras já instaladas para verificar a existência de vagas de estacionamento. É importante ressaltar que questões legais, de segurança e privacidade no uso de câmeras para detecção de vagas de estacionamento estão fora do escopo desta dissertação. Neste trabalho é abordado o problema de como utilizar câmeras de forma oportunista para detecção de vagas de estacionamento. A ideia para a solução é que por intermédio de sistemas embarcados, adaptado-os às câmeras já instaladas na cidade, podemos conceber satisfatoriamente a detecção de vagas. O objetivo principal deste trabalho é apresentar a viabilidade da utilização de sistemas embarcados para detecção de vagas de estacionamento. Para tal são propostas três técnicas de processamento de imagens para resolução do problema e como principal contribuição temos a apresentação de uma arquitetura distribuída para utilização de câmeras de forma oportunista para obtenção das imagens. As principais contribuições deste trabalho são a avaliação de três técnicas de processamento de imagens para detecção de veículos; proposta de uma arquitetura distribuída e oportunista utilizando câmeras para detecção de vagas de estacionamento; uma avaliação comparativa entre a arquitetura proposta e outras duas arquiteturas existentes; e um algoritmo de roteamento para encaminhamento das requisições na arquitetura Embutida. Inicialmente foram avaliadas três técnicas propostas de processamento de imagens para detecção de vagas de estacionamento, sendo a melhor delas a Dilatação após Detecção de Borda com uma eficácia de aproximadamente 100%. Essa avaliação serviu para escolhermos a técnica usada no restante do trabalho. Após a escolha da técnica, realizamos um experimento utilizando a arquitetura proposta e outras duas que serviram para comparação. O resultado do experimento demonstrou a viabilidade da utilização da arquitetura Embutida. Como realizar experimentos de grande porte é uma tarefa complexa, foi desenvolvida uma simulação utilizando o simulador de redes Sinalgo para analisar quatro variáveis no sistema (raio de comunicação, quantidade de câmeras auxiliares, quantidade de requisições simultâneas e percentual de falhas nas câmeras). Com o resultado da simulação pode-se concluir que os fatores com maior influência na variação dos tempos médios das requisições são o tamanho do raio de comunicação e a quantidade de câmeras auxiliares.

O uso de sistemas de assistência ao motorista (DAS) baseados em visão tem contribuído consideravelmente na redução de acidentes e consequentemente no auxílio de uma melhor condução. Estes sistemas utilizam basicamente uma câmera de vídeo embarcada (normalmente fixada no para-brisa) com o propósito de extrair informações acerca da rodovia e ajudar o condutor num melhor processo de dirigibilidade. Pequenas distrações ou a perda de concentração podem ser suficientes para que um acidente ocorra. Este trabalho apresenta uma proposta para o desenvolvimento de algoritmos para extrair informações sobre a sinalização em rodovias. Mais precisamente, serão abordados algoritmos de calibração de câmera explorando a geometria da pista, de extração da marcação de pintura (sinalização horizontal) e detecção e identificação de placas de trânsito (sinalização vertical). Os resultados experimentais indicam que o método de calibração de câmera alcançou bons resultados na obtenção dos parâmetros extrínsecos com erros inferiores a 0:5 . O erro médio encontrado nos experimentos com relação a estimativa da altura da câmera foi em torno de 12 cm (erro relativo aproximado de 10%), permitindo explorar o uso da realidade aumentada como uma possível aplicação. A acurácia global para a detecção e reconhecimento da sinalização horizontal (marcas seccionadas, contínuas e mistas) foi acima de 96% perante uma diversidade de situações apresentadas, tais como: sombras, variação de iluminação, degradação do asfalto e pintura. O uso da câmera calibrada para a detecção da sinalização vertical contribui para delimitar o espaço de varredura da janela deslizante do detector, bem como realizar a procura por placas em uma única escala para cada região de busca, caracterizada pela distância ao veículo. Os resultados apresentados reportam uma taxa global de classificação de aproximadamente 99% para o sinal de proibido ultrapassar, considerando-se uma base de dados limitada a 962 amostras. / The use of driver assistance systems (DAS) based on computer vision has helped considerably in reducing accidents and consequently aid in better driving. These systems primarily use an embedded video camera (usually fixed on the windshield) for the purpose of extracting information about the highway and assisting the driver in a better handling process. Small distractions or loss of concentration may be sufficient for an accident to occur. This work presents the development of algorithms to extract information about traffic signs on highways. More specifically, this work will tackle a camera calibration algorithm that exploits the geometry of the road track, algorithms for the extraction of road marking paint (lane markings) and detection and identification of vertical traffic signs. Experimental results indicate that the proposed method for obtaining the extrinsic parameters achieve good results with errors of less than 0:5 . The average error in our experiments, related to the camera height, were around 12 cm (relative error around 10%). Global accuracy for the detection and classification of road lane markings (dashed, solid, dashed-solid, solid-dashed or double solid) were over 96%. Finally, our camera calibration algorithm was used to reduce the search region and to define the scale of a slidingwindow detector for vertical traffic signs. The use of the calibrated camera for the detection of traffic signs contributes to define the scanning area of the sliding window and perform a search for signs on a unique scale for each region of interest, determined by the distance to the vehicle. The results reported a global classification rate of approximately 99% for the no overtaking sign, considering a limited of 962 samples.

Grâce aux progrès récents dans le domaine des nanotechnologies il est maintenant possible de colorer des plaques de verre avec du dioxyde de titane contenant de l’argent par irradiation laser. L’une des caractéristiques de ce procédé est que le rendu couleur des échantillons produits diffère quand ceux-ci sont observés en réflexion (spéculaire ou diffuse) ou en transmission, ainsi que quand on polarise la lumière. Ce nouveau procédé d’impression laser que l’on a appelé PICSLUP (pour Photo-Induced Colored Silver LUster Printing system) permet de produire des images couleur gonio-apparentes.L’objectif de cette thèse est de caractériser l’apparence couleur (d’un point de vus colorimétrique et photométrique, et ce selon plusieurs géométries d’observation) de plaques de verre colorées par ce procédé. Ce qui pose de nombreux challenges techniques du fait que le système d’impression utilisé est encore en cours de développement et pas souvent accessible, du fait également de plusieurs spécificités photométriques (surface fortement translucide, fortement spéculaire, forte gonio-chromaticité). Afin de lever de toutes ces contraintes techniques notre première approche a été de caractériser la couleur grâce à un imageur monté sur un microscope. Nous avons pour cela généré par impression laser (avec le système PICSLUS) tout un ensemble d’échantillons couleur en faisant varier de manière exhaustive différents paramètres d’impression (temps d’exposition du faisceau laser, longueur d’onde, distance focale). Afin d’obtenir des mesures couleur précises nous avons ensuite développé une méthode de calibrage couleur spécifique dédiée à la mesure de surfaces fortement spéculaires. La précision de cette méthode de calibrage, appliquée aux échantillons créés par le système PICSLUP, est comparable à celles relevées dans l’état de l’art. À partir des couleurs obtenues on peut estimer la gamme des couleur (color gamut) qui peut être obtenue par ce système d’impression, en particulier pour la géométrie spéculaires 0º:0º, et étudier l’influence des différents paramètres d’impression ainsi que l’effet de la polarisation. Quoique les mesures réalisées sous microscope avec la géométrie spéculaire 0°:0° soient particulièrement utile pour étudier les propriétés colorimétriques et photométriques produites par le système PICSLUP, ces mesures ne sont pas suffisantes pour caractériser complètement ce système. En effet, l’apparence couleur des échantillons produits varie également en fonction de la géométrie d’éclairement et d’observation, il est donc nécessaire de caractériser le système PICSLUP selon d’autres géométries que la seule géométrie 0°:0°. Nous avons donc développé une autre méthode de caractérisation basée sur l’utilisation d’un imageur hyperspectral à géométrie ajustable, ce qui nous a permis de caractériser un ensemble donné d’échantillons couleur produits par le système PICSLUP. Ces échantillons ont été mesurés, en recto-verso, en transmission (avec la géométrie 0°:0°), en réflexion spéculaire (avec la géométrie 15°:15°), et en réflexion hors spéculaire (avec la géométrie 45°:0°). Grâce à ces mesures on a pu estimer pour différentes géométries d’observation les changements de gamme des couleurs qui peuvent être obtenus par le système PICSLUP. Le volume qui circonscrit chacune de ces gammes de couleur peut être modélisé par une forme concave qui contient beaucoup de zones éparses, ce qui revient à dire que certaines couleurs ne peuvent être directement obtenues par impression. Afin d’obtenir une forme convexe, plus dense quelque soit la zone d’étude considérée, nous avons testé avec succès une nouvelle méthode d’impression qui consiste non plus à imprimer des aplats (zones uniformément colorées par juxtaposition de lignes laser identiques) mais à imprimer des demi-tons (par juxtaposition de lignes laser de différentes couleurs). Cette méthode est basée sur le principe de l’halftoning et sur un nombre limité de primaires couleur pré-sélectionnées / Recent progresses in nanotechnologies enabled the coloration of glass plates coated with titanium dioxide containing silver by laser irradiation. The colored samples display very different colors when obtained by reflection or transmission of light; in specular or off-specular directions; and with or without polarizing filters. This new laser printing technology, that we call PICSLUP (for Photo-Induced Colored Silver LUster Printing system), enables the production of gonioapparent color images.The goal of this study is to perform a multi-geometry photometric and color characterization of this complex system. This task posed technical challenges due to the system being in a development stage, especially a low availability of the printing material; and due to the photometric properties of the prints: high translucency, high specularity and strong goniochromaticity. In order to overcome these constraints, our first approach was based on color characterization by microscope imaging. The data set used consisted in printing an exhaustive number of micrometric color patches, produced by varying the different laser printing parameters: exposure time, laser wavelength, laser power, and laser focusing distance. To achieve accurate color measurements with samples produced with the PICSLUS system, we successfully developed a color calibration method especially tailored for highly specular materials, whose accuracy is good in comparison to previous studies in the literature on camera color calibration. From the colors obtained, we could estimate the color gamut in the 0º:0º specular reflection geometry and study the influence of the different printing parameters as well as polarization. Although the measurements with microscope imaging in the 0°:0° specular geometry were very useful to study the properties of the colors produced by the PICSLUP technology, they were not sufficient to fully characterize the system, since the samples exhibit very different colors according to the respective positions of the viewer and the light source. With this in mind, we assembled a geometry-adjustable hyperspectral imaging system, which allowed us to characterize a representative subset of the colors that can be produced with the system. The samples were measured from both recto and verso faces, in the 0°:0° transmission, 15°:15° specular reflection, and 45°:0° off-specular reflection illumination/observation geometries. From these measurements, the color gamuts of the system were estimated in the different geometries. The volumes delimited by the colors obtained were concave and contained many sparse regions with very few samples. In order to obtain more continuous, dense and convex color gamut volumes, we successfully tested the generation of new colors by juxtaposing printed lines of different primaries with halftoning techniques. In order to circumvent the need to physically characterize all the different color that can be produced with halftoning using the numerous primaries available, we also tested and fitted existing halftoning prediction models, and obtained a satisfactory accuracy. The use of halftoning not only increased the number colors that can be produced by the system in the different geometries, but also increased the number of different primaries that can be produced when we consider as a whole the set of colors produced by the same printed patch in multiple geometries. Finally, based on the different properties demonstrated by the samples produced by the PISCLUP system, we explored some imaging and security features with colors obtained from our characterization, and propose further potential applications for this new goniochromatic laser printing technology

Made available in DSpace on 2016-12-08T16:52:09Z (GMT). No. of bitstreams: 1 LauSantos.pdf: 561567 bytes, checksum: e1bb1d4fdc16634963128cb2e60b8285 (MD5) Previous issue date: 2011-10-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study broaches some possibilities about the actor relation with the camera and the categories of presence which I identify in the contemporary scene. In this sense, I search for demonstrating the importance of the scenic presence in the space formed by the encounter between the tele/spectator (the viewer) and the actor/actress. In order that, the research was developed fundamentally by the dialogue among the philosophical reflections of phenomenology by Martin Heidegger (the dasein concept) and the experience of the actors: Yoshi Oída and Ryszard Cieslak. In the second moment will be focusing the problematic about the relationship manner between the actor/actress with the camera, as well as, the following categories: tele/presence, co/presence, through the analyzing of the Somatic spectacle. To conclude, I submit and analyze an audiovisual experience developed together with the Cia Pã Theater. This study is divided in three parts (chapters) by the intention that each one has been looked as a photogram, an independent fragment, in order to find on the other parts, the reason of his own presence / Esse estudo aborda algumas possibilidades da relação do ator com a câmera e as categorias de presença que identifico na cena contemporânea. Neste sentido, busco demonstrar a importância da presença cênica no espaço constituído a partir do encontro entre o tele/espectador e o ator/atriz. Para tanto, a pesquisa foi desenvolvida tendo como fundamento o diálogo entre as reflexões filosóficas da fenomenologia de Martin Heidegger (conceito de Dasein) e as experiências dos atores Yoshi Oida e Ryszard Cieslak. Em um segundo momento será problematizado a forma como o ator/atriz se relaciona com a câmera e as categorias: tele/presença e co/presença, através da análise do espetáculo Somático. Para finalizar, apresento e analiso uma experiência audiovisual desenvolvida junto a Cia Pã de Teatro. O presente estudo é divido em 3 partes (capítulos), cuja intenção é que cada uma das partes seja vista como um fotograma, ou seja, um fragmento independente que encontre nas outras partes a razão de sua presença

O uso de sistemas de assistência ao motorista (DAS) baseados em visão tem contribuído consideravelmente na redução de acidentes e consequentemente no auxílio de uma melhor condução. Estes sistemas utilizam basicamente uma câmera de vídeo embarcada (normalmente fixada no para-brisa) com o propósito de extrair informações acerca da rodovia e ajudar o condutor num melhor processo de dirigibilidade. Pequenas distrações ou a perda de concentração podem ser suficientes para que um acidente ocorra. Este trabalho apresenta uma proposta para o desenvolvimento de algoritmos para extrair informações sobre a sinalização em rodovias. Mais precisamente, serão abordados algoritmos de calibração de câmera explorando a geometria da pista, de extração da marcação de pintura (sinalização horizontal) e detecção e identificação de placas de trânsito (sinalização vertical). Os resultados experimentais indicam que o método de calibração de câmera alcançou bons resultados na obtenção dos parâmetros extrínsecos com erros inferiores a 0:5 . O erro médio encontrado nos experimentos com relação a estimativa da altura da câmera foi em torno de 12 cm (erro relativo aproximado de 10%), permitindo explorar o uso da realidade aumentada como uma possível aplicação. A acurácia global para a detecção e reconhecimento da sinalização horizontal (marcas seccionadas, contínuas e mistas) foi acima de 96% perante uma diversidade de situações apresentadas, tais como: sombras, variação de iluminação, degradação do asfalto e pintura. O uso da câmera calibrada para a detecção da sinalização vertical contribui para delimitar o espaço de varredura da janela deslizante do detector, bem como realizar a procura por placas em uma única escala para cada região de busca, caracterizada pela distância ao veículo. Os resultados apresentados reportam uma taxa global de classificação de aproximadamente 99% para o sinal de proibido ultrapassar, considerando-se uma base de dados limitada a 962 amostras. / The use of driver assistance systems (DAS) based on computer vision has helped considerably in reducing accidents and consequently aid in better driving. These systems primarily use an embedded video camera (usually fixed on the windshield) for the purpose of extracting information about the highway and assisting the driver in a better handling process. Small distractions or loss of concentration may be sufficient for an accident to occur. This work presents the development of algorithms to extract information about traffic signs on highways. More specifically, this work will tackle a camera calibration algorithm that exploits the geometry of the road track, algorithms for the extraction of road marking paint (lane markings) and detection and identification of vertical traffic signs. Experimental results indicate that the proposed method for obtaining the extrinsic parameters achieve good results with errors of less than 0:5 . The average error in our experiments, related to the camera height, were around 12 cm (relative error around 10%). Global accuracy for the detection and classification of road lane markings (dashed, solid, dashed-solid, solid-dashed or double solid) were over 96%. Finally, our camera calibration algorithm was used to reduce the search region and to define the scale of a slidingwindow detector for vertical traffic signs. The use of the calibrated camera for the detection of traffic signs contributes to define the scanning area of the sliding window and perform a search for signs on a unique scale for each region of interest, determined by the distance to the vehicle. The results reported a global classification rate of approximately 99% for the no overtaking sign, considering a limited of 962 samples.