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Gonio-Spectrophotometer for Low-Uncertainty Bidirectional Scatter Distribution Function (BSDF) Measurements. A. M. Rabal, J. L. Fontecha, A. Ferrero, A. Pons, J. Campos y A. Corróns IFA-CSIC. rabal@ifa.cetef.csic.es. Outline. BSDF. Theory Aims Instrument description Measurement procedure
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Gonio-Spectrophotometer for Low-Uncertainty Bidirectional Scatter Distribution Function (BSDF) Measurements A. M. Rabal, J. L. Fontecha, A. Ferrero, A. Pons, J. Campos y A. Corróns IFA-CSIC rabal@ifa.cetef.csic.es Ciencia y Tecnología del color. Seminario 2009
Outline • BSDF. Theory • Aims • Instrument description • Measurement procedure • Future work Ciencia y Tecnología del color. Seminario 2009
Directional Hemispherical BSDF. Theory Conical Nicodemus, 1977 Ciencia y Tecnología del color. Seminario 2009
Aims • Realization of diffuse reflectance and reflectance/radiance factors standards • Uncertainty from the non-lambertianity in standards • Relation between coloured-objects BSDF and the spatial distribution of the chromatic coordinates Ciencia y Tecnología del color. Seminario 2009
Instrument description Ciencia y Tecnología del color. Seminario 2009
Instrument description Ciencia y Tecnología del color. Seminario 2009
Instrument description Ciencia y Tecnología del color. Seminario 2009
Instrument description Ciencia y Tecnología del color. Seminario 2009
Measurement procedure Direct Auxiliar System Irradiance, E Indirect Ciencia y Tecnología del color. Seminario 2009
X A Z Germer, 1999 Y CoordinatesTransformation X Source Spherical Coordinates BSDF i Degrees of freedom of experiment s i Z s Y Detector Ciencia y Tecnología del color. Seminario 2009
Ideal specular Directional diffuse Uniform diffuse Fitting to a BSDF Model Model HTSG (He, Torrance, Sillion, Greenberg) (1991) Fitting experimental data to a model 0, , BRDFud Ciencia y Tecnología del color. Seminario 2009
Future work • Assessment of the angles for the proper characterization of the BSDF • Determination of the characteristic parameters of the materials: 0, , BSDFud • Relation between BSDF and object appearance: knowledge of object RADIANCE for every direction within the observer frame Ciencia y Tecnología del color. Seminario 2009
Gonio-Spectrophotometer for Low-Uncertainty Bidirectional Scatter Distribution Function (BSDF) Measurements A. M. Rabal, J. L. Fontecha, A. Ferrero, A. Pons, J. Campos y A. Corróns IFA-CSIC rabal@ifa.cetef.csic.es Ciencia y Tecnología del color. Seminario 2009