Chart::Color::Value(3) User Contributed Perl Documentation Chart::Color::Value(3)

Chart::Color::Value - check, convert and measure color values

my @names = Chart::Color::Value::all_names();
my @rgb  = Chart::Color::Value::rgb_from_name('darkblue');
my @hsl  = Chart::Color::Value::hsl_from_name('darkblue');
my @hsl2 = Chart::Color::Value::hsl_from_rgb( 5 ,10, 100);
my $d = Chart::Color::Value::distance_hsl( \@hsl, \@hsl2);

Chart::Color::Value::add_rgb('lucky', [0, 100, 50]);

RGB and HSL values of named colors from the X11 and HTML standard and Pantone report. Allows also reverse search, storage and conversion of color values.

This module is supposed to be used by Chart::Color and not directly by the user (for the most part). It converts a stored color name into its values (rgb, hsl or both) and back. One color can have multiple names. Also nearby (similar) colors can be searched. Own colors can be (none permanently) stored for later reference by name. For this a name has to be chosen, that is not already taken. Independently of that can any color be converted from rgb to hsl and back.

Return error message if RGB value triplet is not valid (in range).

Return error message if HSL value triplet is not valid (in range).

Change RGB triplet to the nearest valid values.

Change HSL triplet to the nearest valid values.

Converting an rgb value triplet into the corresponding hsl

Red, Green and Blue are integer in 0 .. 255. Hue is an integer between 0 .. 359 (hue) and saturation and lightness are 0 .. 100 (percentage). A hue of 360 and 0 (degree in a cylindrical coordinate system) is considered to be the same, this modul deals only with the ladder.

Converting an hsl value triplet into the corresponding rgb (see rgb_from_name and hsl_from_name). Please not that back and forth conversion can lead to drifting results due to rounding.

my @rgb = Chart::Color::Value::rgb_from_hsl(0, 90, 50);
my @rgb = Chart::Color::Value::rgb_from_hsl([0, 90, 50]); # works too
# for real (none integer results), any none zero value works as second arg 
my @rgb = Chart::Color::Value::rgb_from_hsl([0, 90, 50], 'real');

Distance in (linear) rgb color space between two coordinates.

my $d = Chart::Color::Value::distance_rgb([1,1,1], [2,2,2]);  # approx 1.7

Distance in (cylindrical) hsl color space between two coordinates.

my $d = Chart::Color::Value::distance_rgb([1,1,1], [356, 3, 2]); # approx 6

Copyright 2022 Herbert Breunung.

This program is free software; you can redistribute it and/or modify it under same terms as Perl itself.

Herbert Breunung, <lichtkind@cpan.org>

2022-09-05 perl v5.36.0