Incident Light Metering in Computer Graphics
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Date
1998
Journal Title
Journal ISSN
Volume Title
Publisher
Blackwell Publishers Ltd and the Eurographics Association
Abstract
Every rendering process consists of two steps. The first is the computing of luminance values by methods like ray tracing or radiosity, and the second step is the mapping of the computed values to values appropriate for displaying. In the last years, as alternative to simple linear scaling which maps the average value to the medium luminance, some new ways of mapping were introduced. These new methods are based on photography analogies and on human vision models. All existing methods follow, implicitly or explicitly, the reflected light metering principle. The method introduced in this paper is the first that follows the incident light metering used in professional photography and in the movie industry. Actually the irradiances are measured using a set of diffusors, which are placed automatically in the scene, and a linear scale factor based on these measurements is used to map the computed radiances to the display device. The diffusors act as half space integrators, they collect the light energy from all half space directions. The light comes from the primary light sources, or it is the result of various interreflections. The newly introduced method reproduces original colors faithfully even for scenes with very low or very high average reflectivity.
Description
@article{10.1111:1467-8659.00287,
journal = {Computer Graphics Forum},
title = {{Incident Light Metering in Computer Graphics}},
author = {Neumann, Laszlo and Matkovic, Kresimir and Neumann, Attila and Purgathofer, Werner},
year = {1998},
publisher = {Blackwell Publishers Ltd and the Eurographics Association},
ISSN = {1467-8659},
DOI = {10.1111/1467-8659.00287}
}