Programming Web Graphics with Perl and GNU Softwar

Name

luminance — return luminance for a color name

Synopsis

GIFgraph::colour::_luminance(R, G, B)

This method will return the luminance of a color represented by the given RGB list. The luminance is represented as a floating point number in the range to 1, where is black and 1 is white. For example:

use GIFgraph::colour qw(:colours);
print _luminance(255, 105, 180);          # This is a dark pink

will give us a value of .558091470588235. You probably will never need to know a color’s luminance to this degree of precision, but it’s there if you need it.