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Relative Contributions of Internal and External Features to Face RecognitionJarudi, Izzat N., Sinha, Pawan 01 March 2003 (has links)
The central challenge in face recognition lies in understanding the role different facial features play in our judgments of identity. Notable in this regard are the relative contributions of the internal (eyes, nose and mouth) and external (hair and jaw-line) features. Past studies that have investigated this issue have typically used high-resolution images or good-quality line drawings as facial stimuli. The results obtained are therefore most relevant for understanding the identification of faces at close range. However, given that real-world viewing conditions are rarely optimal, it is also important to know how image degradations, such as loss of resolution caused by large viewing distances, influence our ability to use internal and external features. Here, we report experiments designed to address this issue. Our data characterize how the relative contributions of internal and external features change as a function of image resolution. While we replicated results of previous studies that have shown internal features of familiar faces to be more useful for recognition than external features at high resolution, we found that the two feature sets reverse in importance as resolution decreases. These results suggest that the visual system uses a highly non-linear cue-fusion strategy in combining internal and external features along the dimension of image resolution and that the configural cues that relate the two feature sets play an important role in judgments of facial identity.
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Realce Automático de Imagens Subaquáticas em Rios da AmazôniaRodrigues, Daily Daleno de O. 27 February 2015 (has links)
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Previous issue date: 2015-02-27 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / The enhancement of underwater images in applications in the area of Amazonian rivers has
been increasingly required and needs further study especially where the rivers have high
turbidity and low light. There is increasingly demand for automatic enhancement methods to
carry out monitoring of fauna and flora intensive rivers, as well as for the maintenance of
pipelines and underwater cables. The enhancement methods specified, developed and
validated for using in the rivers of the Amazonia are faced with the problem of imaging
quality. The research related to underwater am environments of the Amazon has to dead with
high turbidity of the water, caused mainly due to particles in suspension and interaction of
light with the environment. The underwater images extraction with satisfiable visibility of the
environments of Amazonian rivers has become extremely indispensable and relevant, given
that there are natural treasures still unexplored into the depths of these rivers, as well as there
is need to maintain the underwater part of the transportation system gas LPG (Liquefied
Petroleum Gas) Coari-Manaus. Given this promising scenario, this study aims to improve
these images by applying techniques of enhancement using nonlinear filters, which promote
the minimization of the light interaction characteristics with the environment, loss of contrast
and color in images extracted from turbid underwater environments. The method was
experimentally validated with images acquired from simulations of underwater scenes and
images acquired in outdoor underwater environments. The proposed method is compared to
two other techniques of highlighting or enhancement of images. As in this study, these
techniques also require a single image as input. The results return images with enhanced
visual quality, considering a large set of experiments with simulation data and real outdoors
scenes. / O realce de imagens subaquáticas em aplicações na região dos rios amazônicos é cada vez
mais requisitado e carece de um estudo mais aprofundado especialmente nos casos em que os
rios apresentam alto índice de turbidez e baixa luminosidade. Estes rios têm demandado cada
vez mais métodos de realce automáticos que realizem o monitoramento de sua fauna e flora,
bem como manutenção de dutos e cabos subaquáticos. Os métodos de realce especificados,
desenvolvidos e validados para uso nos rios da região, se deparam com o problema da
qualidade de captação de imagens. As pesquisas relacionadas aos ambientes subaquáticos da
Amazônia são prejudicadas pelo alto nível de turbidez de suas águas, causadas principalmente
devido às partículas em suspensão e à interação da luz com o meio. A extração de imagens
subaquáticas de visibilidade adequada aos ambientes dos rios amazônicos em geral, tem se
demonstrado imprescindível e relevante, haja vista que, existem tesouros naturais ainda
inexplorados nas profundezas desses rios. Por outro lado, verifica-se a necessidade de
manutenção da parte subaquática do sistema de transporte de gás GLP (Gás Liquefeito de
Petróleo) Coari-Manaus. Diante deste cenário promissor, este trabalho objetiva a melhoria
dessas imagens através da aplicação de técnicas de realce com uso de filtros não lineares, que
promovam a minimização das características da interação da luz com o meio, perda de
contraste e cores em imagens extraídas de ambientes subaquáticos turvos. O método proposto
é comparado a duas outras técnicas de realce ou melhoria de imagens que, como neste
trabalho, também requerem uma única imagem como entrada. Os resultados obtidos retornam
imagens com melhor qualidade visual, considerando-se um grande conjunto de experimentos
realizados com dados de simulação e cenas reais obtidas em ambientes externos.
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