PG2014short

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https://diglib.eg.org/handle/10.2312/7750

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Browsing PG2014short by Subject "Color"

Now showing 1 - 3 of 3
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    Automatic Aesthetics-based Lighting Design with Global Illumination
    (The Eurographics Association, 2014) Léon, Vincent; Gruson, Adrien; Cozot, Rémi; Bouatouch, Kadi; John Keyser and Young J. Kim and Peter Wonka
    In computer graphics, lighting plays an important role in the appearance of a scene. A change in the configuration of light sources can lead to different aesthetics in the final rendered image. Lighting design becomes increasingly complex when using sophisticated global illumination techniques. In this paper, we present a new approach to automatically design the lighting configuration according to the aesthetic goal specified by the user as a set of target parameters. Target parameters are used to set up an objective function which is minimized using an optimization method. The results show that our method can be used to automatically design a lighting configuration that will give to the final image a classic photographic look.
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    Perceptually Optimised Illumination for Seamless Composites
    (The Eurographics Association, 2014) Chalmers, Andrew; Choi, Jong Jin; Rhee, Taehyun; John Keyser and Young J. Kim and Peter Wonka
    Realistic illumination in composition is important for a seamless mixture between the virtual and real world objects in visual effects and mixed reality. The seamlessness is the measure of how perceivably apparent the synthetic object in the final composition is, and how indistinguishable it is from the photographed scene. Given that the ultimate receiver of image information is the human eye, the metric is determined by the Human Visual System (HVS). We conducted a series of psychophysical studies to observe and capture the thresholds of the HVS's ability to perceive illumination inconsistencies between the rendered subject and the photographed scene. Based on our observations, we find perceptually optimised thresholds for reducing resources across resolution and dynamic range of the radiance map (RM) for image based lighting (IBL). We evaluated our thresholds to illuminate virtual objects for seamless composition with photographed scenes.
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    Visibility Filtering for Producing Indirect Illumination
    (The Eurographics Association, 2014) Chen, Yu-Jung; Yen, Chen-Yu; Chen, Yen-Yu; Chen, Wei-Chao; Chien, Shao-Yi; John Keyser and Young J. Kim and Peter Wonka
    Indirect illumination is one of the most visually significant effects for a synthesized image. In order to render such effects at interactive rates, it is important to resolve the visibility between surfaces efficiently. In this work, we propose to approximate visibility by representing the scene through point proxies and hash them into voxels. The indirect illumination is then rendered in two stages. First, we cast sparse shadow rays to march and collect visible voxels for each low-resolution deferred pixel. The list of visible voxels are then processed using the proposed Visibility Filter (VF) to collect voxels missed from the first stage. Afterward, we properly weight the visible voxels as light sources to produce the full resolution image. Our method runs at interactive rates at 1.3 fps to 2.3 fps on GPUs with pleasing visual quality, in particular for glossy reflections.