File Coverage

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

Criterion	Covered	Total	%
statement	18	18	100.0
branch			n/a
condition			n/a
subroutine	5	5	100.0
pod	0	2	0.0
total	23	25	92.0

# YUV color space specific code as in BT.601

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

sub from_rgb {
    my ($rgb) = shift;
    my (@yuv) =  mult_matrix_vector_3([[ 0.299   ,  0.587,     0.114    ],
                                       [-0.168736, -0.331264,  0.5      ],
                                       [ 0.5     , -0.418688, -0.081312 ]], @$rgb);
    $yuv[1] += 0.5;
    $yuv[2] += 0.5;
    return \@yuv;
}
sub to_rgb {
    my ($yuv) = shift;
    $yuv->[1] -= 0.5;
    $yuv->[2] -= 0.5;
    my (@rgb) =  mult_matrix_vector_3([[ 1,  0       ,  1.402   ],
                                       [ 1, -0.344136, -0.714136],
                                       [ 1,  1.772   ,  0       ]], @$yuv);
    return \@rgb;
}

Graphics::Toolkit::Color::Space->new(
        alias => 'YPbPr',
        axis  => [qw/luma Pb Pr/], # luma, cyan-orange balance, magenta-green balance
        short => [qw/Y U V/],
        range => [1, [-.5, .5], [-.5, .5],],
      convert => {RGB => [\&to_rgb, \&from_rgb]},
);