]>
Commit | Line | Data |
---|---|---|
1 | package Convert::Color::LUV; | |
2 | ||
3 | use 5.008009; | |
4 | use strict; | |
5 | use warnings; | |
6 | use parent qw/Convert::Color/; | |
7 | ||
8 | use Convert::Color::XYZ; | |
9 | ||
10 | our $VERSION = '0.002'; | |
11 | ||
12 | use constant +{ ## no critic (Capitalization) | |
13 | KAPPA => (29/3) ** 3, | |
14 | EPS => (6/29) ** 3, | |
15 | ||
16 | REF_X => 3127/3290, | |
17 | REF_Z => 3583/3290, | |
18 | }; | |
19 | ||
20 | use constant +{ ## no critic (Capitalization) | |
21 | REF_U => 4 * REF_X / (REF_X + 15 + 3 * REF_Z), | |
22 | REF_V => 9 / (REF_X + 15 + 3 * REF_Z), | |
23 | }; | |
24 | ||
25 | __PACKAGE__->register_color_space('luv'); | |
26 | ||
27 | sub new { | |
28 | my ($class, $l, $u, $v) = @_; | |
29 | ($l, $u, $v) = split /,/s, $l unless defined $u; | |
30 | bless [$l, $u, $v], $class | |
31 | } | |
32 | ||
33 | sub L { shift->[0] } | |
34 | sub u { shift->[1] } | |
35 | sub v { shift->[2] } | |
36 | ||
37 | sub luv { @{$_[0]} } | |
38 | ||
39 | sub _y_to_l { | |
40 | my ($y) = @_; | |
41 | $y <= EPS ? $y * KAPPA : 116 * ($y ** (1/3)) - 16 | |
42 | } | |
43 | ||
44 | sub _l_to_y { | |
45 | my ($l) = @_; | |
46 | $l <= 8 ? $l / KAPPA : (($l + 16) / 116) ** 3 | |
47 | } | |
48 | ||
49 | sub convert_to_xyz { | |
50 | my ($self) = @_; | |
51 | my ($l, $u, $v) = @$self; | |
52 | return Convert::Color::XYZ->new(0, 0, 0) unless $l; | |
53 | my $var_u = $u / (13 * $l) + REF_U; | |
54 | my $var_v = $v / (13 * $l) + REF_V; | |
55 | my $y = _l_to_y $l; | |
56 | my $x = 9 * $y * $var_u / (4 * $var_v); | |
57 | my $z = (9 * $y - (15 * $var_v * $y) - ($var_v * $x)) / (3 * $var_v); | |
58 | Convert::Color::XYZ->new($x, $y, $z) | |
59 | } | |
60 | ||
61 | sub new_from_xyz { | |
62 | my ($class, $xyz) = @_; | |
63 | my ($x, $y, $z) = @$xyz; | |
64 | my $l = _y_to_l $y; | |
65 | return $class->new(0, 0, 0) unless $l; | |
66 | my $var_u = (4 * $x) / ($x + 15 * $y + 3 * $z); | |
67 | my $var_v = (9 * $y) / ($x + 15 * $y + 3 * $z); | |
68 | my $u = 13 * $l * ($var_u - REF_U); | |
69 | my $v = 13 * $l * ($var_v - REF_V); | |
70 | $class->new($l, $u, $v) | |
71 | } | |
72 | ||
73 | sub rgb { shift->convert_to_xyz->rgb } | |
74 | sub new_rgb { shift->new_from_xyz(Convert::Color::XYZ->new_rgb(@_)) } | |
75 | ||
76 | 1; | |
77 | __END__ | |
78 | ||
79 | =encoding utf-8 | |
80 | ||
81 | =head1 NAME | |
82 | ||
83 | Convert::Color::LUV - a color value in the CIE 1976 (L*, u*, v*) color space | |
84 | ||
85 | =head1 SYNOPSIS | |
86 | ||
87 | use Convert::Color::LUV; | |
88 | my $red = Convert::Color::LUV->new(53.23711, 175.00982, 37.76509); | |
89 | my $green = Convert::Color::LUV->new('87.73552,-83.06712,107.41811'); | |
90 | ||
91 | use Convert::Color; | |
92 | my $blue = Convert::Color->new('luv:32.30087,-9.40241,-130.35109'); | |
93 | ||
94 | say $red->L; # 53.23711 | |
95 | say $red->u; # 175.00982 | |
96 | say $red->v; # 37.76509 | |
97 | say join ',', $blue->luv; # 32.30087,-9.40241,-130.35109 | |
98 | ||
99 | =head1 DESCRIPTION | |
100 | ||
101 | Objects of this class represent colors in the CIE 1976 (L*, u*, v*) color space. | |
102 | ||
103 | Methods: | |
104 | ||
105 | =over | |
106 | ||
107 | =item Convert::Color::LUV->B<new>(I<$l>, I<$u>, I<$v>) | |
108 | ||
109 | Construct a color from its components. | |
110 | ||
111 | =item Convert::Color::LUV->B<new>(I<"$l,$u,$v">) | |
112 | ||
113 | Construct a color from a string. The string should contain the three | |
114 | components, separated by commas. | |
115 | ||
116 | =item $luv->B<L> | |
117 | ||
118 | =item $luv->B<u> | |
119 | ||
120 | =item $luv->B<v> | |
121 | ||
122 | Accessors for the three components of the color. | |
123 | ||
124 | =item $luv->B<luv> | |
125 | ||
126 | Returns the three components as a list. | |
127 | ||
128 | =back | |
129 | ||
130 | =head1 SEE ALSO | |
131 | ||
132 | L<Convert::Color> | |
133 | ||
134 | =head1 AUTHOR | |
135 | ||
136 | Marius Gavrilescu, E<lt>marius@ieval.roE<gt> | |
137 | ||
138 | =head1 COPYRIGHT AND LICENSE | |
139 | ||
140 | Copyright (C) 2015 by Marius Gavrilescu | |
141 | ||
142 | This library is free software; you can redistribute it and/or modify | |
143 | it under the same terms as Perl itself, either Perl version 5.20.2 or, | |
144 | at your option, any later version of Perl 5 you may have available. | |
145 | ||
146 | ||
147 | =cut |