865 resultados para digitalizador de imagens


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research presents a methodology for prediction of building shadows cast on urban roads existing on high-resolution aerial imagery. Shadow elements can be used in the modeling of contextual information, whose use has become more and more common in image analysis complex processes. The proposed methodology consists in three sequential steps. First, the building roof contours are manually extracted from an intensity image generated by the transformation of a digital elevation model (DEM) obtained from airborne laser scanning data. In similarly, the roadside contours are extracted, now from the radiometric information of the laser scanning data. Second, the roof contour polygons are projected onto the adjacent roads by using the parallel projection straight lines, whose directions are computed from the solar ephemeris, which depends on the aerial image acquisition time. Finally, parts of shadow polygons that are free from building perspective obstructions are determined, given rise to new shadow polygons. The results obtained in the experimental evaluation of the methodology showed that the method works properly, since it allowed the prediction of shadow in high-resolution imagery with high accuracy and reliability.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In general, a land-based mobile mapping system is featured by a vehicle with a pair of video cameras mounted on the top and positioning and navigation sensors loaded in the vehicle. Considering the pair of video cameras mounted on the roof of the vehicle as a stereo camera pointing forward with both optical axes parallel to each other and orthogonal to the stereo base, whose length is 0.94 m, this paper aims at analyzing the interior and exterior camera orientation and the object point coordinates estimated by phototriangulation when the length constraint related to the stereo base is considered or not. The results show that the stereo base constraint has effect ouver the convergence estimation, but does it neither improves the object point coordinate estimation at significance level of 5% and nor it influences the interior orientation parameters. Finally, it has been noticed that the optical axes are not truly parallel to each other and orthogonal to the stereo base. Additionally, it has been observed that there is a convergence of approximately 0.5 degrees in the optical axes and they are not in the same plane (approximately 0.8 degrees deviation).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper a methodology for automatic extraction of road segments from images with different resolutions (low, middle and high resolution) is presented. It is based on a generalized concept of lines in digital images, by which lines can be described by the centerlines of two parallel edges. In the specific case of low resolution images, where roads are manifested as entities of 1 or 2 pixels wide, the proposed methodology combines an automatic image enhancement operation with the following strategies: automatic selection of the hysteresis thresholds and the Gaussian scale factor; line length thresholding; and polygonization. In medium and high resolution images roads manifest as narrow and elongated ribbons and, consequently, the extraction goal becomes the road centerlines. In this case, it is not necessary to apply the previous enhancement step used to enhance roads in low resolution images. The results obtained in the experimental evaluation satisfied all criteria established for the efficient extraction of road segments from different resolution images, providing satisfactory results in a completely automatic way.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Helena is the romance of perishable and discontinuous title character denominator of a dialectic that does not consume and build the narrative by sequential fragmentation combined with episodic frame. The novel is a lightning stroke to the romantic literary project. Therefore, this study aims to find "objective" elements of the novel that would constitute a conception of literary nation proposed by Machado de Assis, as in classical writing, where women are engaged as a metaphor for the nation by a non-cultural heroism, as the example of the Greek myth of Helena, where the feminine represents a mythical image of the nation. The paper's theoretical conception of the history of Walter Benjamin, that is, that is constructed as an allegorical appeal, the conclusions about the disciplinary society of nineteenth century of Michel Foucault, the construction of the nation as a subtle game to remember and forget of Wander Miranda and the rhetoric of death and loss reflected in the speeches of the cultural heritage of José Reginaldo Santos Gonçalves, which allow you to analyze the work permeated by subjectivity and existential conflicts by Machado, who has it arranged in dialectic with the avant-garde literary romanticism and realism. In this relationship with the Greek myth of Helen, explained that characters with the nickname of Helena in Machado's work are not uncommon. As in classical Helena, Machado s Helena uses three rhetorical are the cause of the seizure of the nation. In this game of remembering and forgetting, in the daily plebiscite, Machado draw ideal images that forged our mythical past and commitment to the future. The suffering love of Helena is suffering from failure of the nation which would have led the author to the use of allegorical language, seeking a balance in the chaos generated by the opposition between cruelty and pity widespread view in an area where only left the character's confession guilt for the death. It is a simulacrum of unfinished nation, the space for the game of remembering and forgetting, while the rhetoric of negotiation of our Brazilianness

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article proposes a method for 3D road extraction from a stereopair of aerial images. The dynamic programming (DP) algorithm is used to carry out the optimization process in the object-space, instead of usually doing it in the image-space such as the DP traditional methodologies. This means that road centerlines are directly traced in the object-space, implying that a mathematical relationship is necessary to connect road points in object and image-space. This allows the integration of radiometric information from images into the associate mathematical road model. As the approach depends on an initial approximation of each road, it is necessary a few seed points to coarsely describe the road. Usually, the proposed method allows good results to be obtained, but large anomalies along the road can disturb its performance. Therefore, the method can be used for practical application, although it is expected some kind of local manual edition of the extracted road centerline.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper is a totally automatic strategy proposed to reduce the complexity of patterns ( vegetation, building, soils etc.) that interact with the object 'road' in color images, thus reducing the difficulty of the automatic extraction of this object. The proposed methodology consists of three sequential steps. In the first step the punctual operator is applied for artificiality index computation known as NandA ( Natural and Artificial). The result is an image whose the intensity attribute is the NandA response. The second step consists in automatically thresholding the image obtained in the previous step, resulting in a binary image. This image usually allows the separation between artificial and natural objects. The third step consists in applying a preexisting road seed extraction methodology to the previous generated binary image. Several experiments carried out with real images made the verification of the potential of the proposed methodology possible. The comparison of the obtained result to others obtained by a similar methodology for road seed extraction from gray level images, showed that the main benefit was the drastic reduction of the computational effort.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this work a method is proposed to allow the indirect orientation of images using photogrammetric control extracted through integration of data derived from Photogrammetry and Light Detection and Ranging (LiDAR) system. The photogrammetric control is obtained by using an inverse photogrammetric model, which allows the projection of image space straight lines onto the object space. This mathematical model is developed based on the intersection between the collinearity-based straight line and a DSM of region, derived from LiDAR data. The mathematical model used in the indirect orientation of the image is known as the model of equivalent t planes. This mathematical model is based on the equivalence between the vector normal to the projection plane in the image space and to the vector normal to the rotated projection plane in the object space. The goal of this work is to verify the quality, efficiency and potential of photogrammetric control straight lines obtained with proposed method applied to the indirect orientation of images. The quality of generated photogrammetric control was statistically available and the results showed that proposed method is promising and it has potential for the indirect orientation of images.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

La valeur évocative, magique ou my(s)thique attribuée à la relation homme/animal peut être observée dans la culture depuis les époques lointaines. Dans la symbologie animale on trouve une immense charge sémantique justifiant les croyances les plus anciennes que les êtres humains ont déjà eues. Les animaux sont à la base du symbolisme mythique et ils se constituent en tant qu une source pour la riche production artistique englobant une grande variété iconographique et des textes de nature diverse. Ayant comme référence de la symbologie animal l image my(s)thique du chat, on observe la façon par laquelle le langage poétique contemple les profils mythiquesymboliques qui ont un rapport avec ce langage, tout en mettant en relief ceux qui ont des rapports aux relations entre le monde humain et le félin. À partir de l antologie tématique Assinar a pele ; des concepts théoriques ; et des abordages mitocritiques, nous cherchons à analyser les façons par lesquelles les différentes images mythiques associées au chat ont été explorées par la poésie. La définition d une typologie englobant des catégories telles : chat domestique, chat de rue, chat femme, chat nocturne, chat démoniaque et chat divin, parmi d autres, soutient la reconnaissance d identités possibles entre ces poèmes et signale la répétition d un répertoire symbolique divers en soi, mais, cohérent avec la présence du chat dans la société humaine à travers les temps

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O objetivo desta investigação foi elaborar e experimentar procedimentos avaliativos que buscaram acessar as aprendizagens propiciadas em aulas de Educação Física que se valeram de matérias televisivas. A metodologia utilizada foi a pesquisa-ação. Concluiu-se que os alunos aprofundaram sua percepção e entendimento sobre o tema desenvolvido nas aulas (exclusão/discriminação); que as estratégias utilizadas contemplaram uma avaliação integrada ao processo de ensino e aprendizagem; e que o uso da matéria televisiva escolhida deu-se de forma integrada ao processo, caracterizando-se como imprescindível para o seu desenvolvimento.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aims of this dissertation is to study formation of the Dutch view seeing the colonial scenery in screens by Frans Post, as well as, to perceive a colonial world constitution through landscape paintings by him with his natural and human representation. The artist was the first to portray South American views, after he landed in Pernambuco with retinue of Dutch governor of colony, John Maurice, Prince of Nassau-Siegen. Post, by his 24 years old, was designated to represent for Dutch people their colony. The text reflects on visual construction of natural and human aspects in landscapes by Dutchman and how that aspects were included in colonizer imaginary about the strange world of America. European (Dutch) look about their conquered possessions in the New World was charged with exoticism and imagination. In order to understand that view, it`s paramount to study imaginary pictures reared by Frans Post, on his return to the Netherlands, and notions of landscape and exotic, wild and unspoiled nature which the Dutch people had when they thought about the Dutch colony in America. Our principal (visual) sources of research are six paintings: Vista da Sé de Olinda (1662), Vista das ruínas de Olinda (undated), Engenho (undated), Engenho (1660), Vista da cidade Maurícia e do Recife (1653), e Paisagem com rio e tamanduá (1649), all these canvases were painted when Frans Post returned to Europe. We seek to work through a methodology that focuses on investigation of primary visual and textual material, because these textual and pictorial representations reflect the 17th-century colonial view of colonial history themes of the - here called - Dutch America

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Iconic historical figure, Antônio Vieira (1608-1697) is regarded as an essential character to the Luso-Brazilian history. Between 1646 and 1667, the priest began writing the History of the Future, the first volume of the celebrated "Clavis Prophetarum , political and theological unity that would leverage the process of spread of Christianity across the globe, recognizing Portugal as forefront and center of all millenarian movement. Them, Jesuit represented the "World" in two metaphors: "theater" and "body" responsible for viewing spaces of abstract Christian truth. Starting from the hermeneutical assumptions of analysis, we investigated the historical relations present in the construction of such representations, by which establish the dialogue between politics, theology and seventeenth-century rhetoric. Therefore, the following study supports the hypothesis that beyond a mere stylistic expressions, spatial metaphors of "World" were formulated by Antonio Vieira as a resource that could sharpen the minds of his readers, engaging words into action, become alive and effective use of rhetoric

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Digital image processing is a field that demands great processing capacity. As such it becomes relevant to implement software that is based on the distribution of the processing into several nodes divided by computers belonging to the same network. Specifically discussed in this work are distributed algorithms of compression and expansion of images using the discrete cosine transform. The results show that the savings in processing time obtained due to the parallel algorithms in comparison to its sequential equivalents is a function that depends on the resolution of the image and the complexity of the involved calculation; that is efficiency is greater the longer the processing period is in terms of the time involved for the communication between the network points.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this work, we propose a multi agent system for digital image steganalysis, based on the poliginic bees model. Such approach aims to solve the problem of automatic steganalysis for digital media, with a case study on digital images. The system architecture was designed not only to detect if a file is suspicious of covering a hidden message, as well to extract the hidden message or information regarding it. Several experiments were performed whose results confirm a substantial enhancement (from 67% to 82% success rate) by using the multi-agent approach, fact not observed in traditional systems. An ongoing application using the technique is the detection of anomalies in digital data produced by sensors that capture brain emissions in little animals. The detection of such anomalies can be used to prove theories and evidences of imagery completion during sleep provided by the brain in visual cortex areas