# # This software is Copyright 2005 by Elsevier Inc. You may use it # under the terms of the license at http://perl.plover.com/hop/LICENSE.txt . # ### ### RGB_to_CMYK ### ## Chapter 3 section sub RGB_to_CMYK { my ($r, $g, $b) = @_; my ($c, $m, $y) = (255-$r, 255-$g, 255-$b); my $k = $c < $m ? ($c < $y ? $c : $y) : ($m < $y ? $m : $y); # Minimum for ($c, $m, $y) { $_ -= $k } [$c, $m, $y, $k]; }