The equal contrast gray scale

Auteur :
WILLIAMSON, G. R.

Description :
Research to date on equal value gray scales has produced results that are in disagreement. This may be attributed both to the experimental techniques used and the bounded nature of the gray spectrum. This study employs a task directly analogous to that faced by map readers trying to distinguish gray tones on a classed choropleth map: the measurement of perceived contrast between gray tone pairs. Equal contrast scales of five to ten tones are iteratively calculated using trend surface équation. Power functions are calculated for each of these six equal constrast gray scales and for the combination of all of them.


Type de document :
Article de périodique

Source :
American cartographer Washington, 1982, vol. 9, n°. 2, p. 131-139, Références bibliographiques : 14 réf.

Date :
1982