Crossword clues for reflectance
Wiktionary
n. (context physics English) The ratio of the flux reflected to that incident on a surface
WordNet
n. the fraction of radiant energy that is reflected from a surface [syn: coefficient of reflection, reflection factor, reflectivity]
Wikipedia
Reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at an interface. The reflectance spectrum or spectral reflectance curve is the plot of the reflectance as a function of wavelength.
Usage examples of "reflectance".
The shaft of sunlight would drift visibly in the course of the interview, but at the editing stage everything could be stripped back to reflectance values, and recomputed with a fixed set of rather more flattering light sources.
Thus a reflectance change shows itself as step edge in an image, while illuminance changes gradually over space.
By this argument one can separate reflectance change from illuminance change by taking spatial derivatives: High derivatives are due to reflectance and low ones are due to illuminance.
The luminance image can be considered to be the product of two other images‚ the reflectance image and the illuminance image.
This must mean that illuminance and reflectance images are not arbitrary functions.
This solves part of the lightness problem, but not all of it, the absolute reflectances remain unknown.
The small arrows in the panels show how the various reflectances are mapped to their corresponding luminances.
The shaded area within the arrows shows how a typical range of reflectances will be mapped into the corresponding range of luminances.
An observer cannot see the reflectances "directly", but rather requires an atmospheric transfer function to convert reflectances to luminances.
The algorithm then reintegrates edge information over space to reconstruct the reflectance image.