CEIG09

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https://diglib.eg.org/handle/10.2312/895

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Browsing CEIG09 by Subject "Categories and Subject Descriptors (according to ACM CCS): Computing Methodologies [I.3.7]: Computer Graphics - 3D Graphics; Computing Methodologies [I.4.10]: Image Processing and Computer Vision - Image Representation"

Now showing 1 - 2 of 2
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    Light Source Detection in Photographs
    (The Eurographics Association, 2009) Lopez-Moreno, Jorge; Hadap, Sunil; Reinhard, Erik; Gutierrez, Diego; Carlos Andujar and Javier Lluch
    Common tasks related to image processing or augmented reality include rendering new objects into existing images, or matching objects with unknown illumination. To facilitate such algorithms, it is often necessary to infer from which directions a scene was illuminated, even if only a photograph is available. For this purpose, we present a novel light source detection algorithm that, contrary to the current state-of-the-art, is able to detect multiple light sources with sufficient accuracy. 3D measures are not required, only the input image and a very small amount of unskilled user interaction.
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    Where are the Lights? Measuring the Accuracy of Human Vision
    (The Eurographics Association, 2009) Lopez-Moreno, Jorge; Sangorrin, Francisco; Latorre, Pedro; Gutierrez, Diego; Carlos Andujar and Javier Lluch
    In real life, light sources are frequently not present in our view field. However human vision is able to infer the illumination just by observing its effect on visible objects (serving as lightprobes) or, inverting the idea, it is able to spot an object which is incoherently lit in a composition. These lightprobes have been used by computer algorithms in the same manner to detect lights, mimicking the human visual system (HVS). It has been proved that the presence of shadows or highlights in the lightprobe affects the accuracy of HVS, although its degree of influence remains unbeknownst until now. The present work performs a psychophysical analysis which aims to provide accurate data for light detection, perception-oriented rendering, image compositing and augmented reality.