File Coverage

lib/Graphics/Toolkit/Color/Space/Instance/CIEXYZ.pm

Criterion	Covered	Total	%
statement	18	18	100.0
branch	4	4	100.0
condition			n/a
subroutine	7	7	100.0
pod	0	4	0.0
total	29	33	87.8

# CIEXYZ color space specific code for Illuminant D65 and Observer 2°

package Graphics::Toolkit::Color::Space::Instance::CIEXYZ;
use v5.12;
use warnings;
use Graphics::Toolkit::Color::Space qw/mult_matrix_vector_3/;

my @D65 = (0.95047, 1, 1.088830);

# change normalized RGB values to and from standard observer 2°
sub apply_observer  { $_[0] > 0.04045  ? ((($_[0] + 0.055) / 1.055 ) ** 2.4) : ($_[0] / 12.92) }
sub remove_observer { $_[0] > 0.003131 ? ((($_[0]**(1/2.4)) * 1.055) - 0.055) : ($_[0] * 12.92) }

sub from_rgb {
    my ($rgb) = shift;
    my @rgb = map {apply_observer( $_ )} @$rgb;
    return [ mult_matrix_vector_3([[0.433949941, 0.37620977,  0.18984029], # conversion + normalisation
                                   [0.2126729,   0.7151522,   0.0721750],
                                   [0.017756583, 0.109467961, 0.872775456]], @rgb) ];
}
sub to_rgb {
    my ($xyz) = shift;
    my @rgb = mult_matrix_vector_3([[  3.07996,   -1.53714 , -0.542816 ],
                                    [ -0.921259 ,  1.87601 ,  0.0452475],
                                    [  0.0528874, -0.204026,  1.15114  ]], @$xyz);
    return [ map { remove_observer($_) } @rgb ];
}

Graphics::Toolkit::Color::Space->new(
       alias => 'CIEXYZ',
        axis => [qw/X Y Z/],
       range => [map {$D65[$_] * 100} 0 .. 2],
   precision => 3,
     convert => {RGB => [\&to_rgb, \&from_rgb]},
);