-
Notifications
You must be signed in to change notification settings - Fork 3
/
replace_color.pl
113 lines (78 loc) · 2.32 KB
/
replace_color.pl
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
#!perl -w
use strict;
use Imager;
=head1 NAME
replace_color - replace one color with another in an image
=head1 SYNOPSIS
perl replace_color fromcolor tocolor inimage outimage
=head1 DESCRIPTION
This is a simple demonstration of Imager::transform2 that replaces one
color with another in an image.
Note: this works with full color images, and always produces a 3
channel output image - the alpha channel (if any) is not preserved.
Most of the work is done in the replace_color() function.
=over
=cut
# extract parameters
my $from = shift;
my $to = shift;
my $in = shift;
my $out = shift
or die "Usage: $0 fromcolor tocolor inimage outimage\n";
# convert the colors into objects
my $from_color = Imager::Color->new($from)
or die "Cannot convert fromcolor $from into a color: ", Imager->errstr, "\n";
my $to_color = Imager::Color->new($to)
or die "Cannot convert tocolor $to into a color: ", Imager->errstr, "\n";
# do the work
my $img = Imager->new;
$img->read(file=>$in)
or die "Cannot read image $in: ", $img->errstr, "\n";
my $result = replace_color($img, $from_color, $to_color)
or die "Cannot replace colors: ", Imager->errstr, "\n";
$result->write(file=>$out)
or die "Cannot write image $out: ", $result->errstr, "\n";
=item replace_color
Called:
my $result = replace_color($in_image, $from_color, $to_color);
Returns a new image object with colors replaced.
=cut
sub replace_color {
my ($img, $from_color, $to_color) = @_;
my ($from_red, $from_green, $from_blue) = $from_color->rgba;
my ($to_red, $to_green, $to_blue) = $to_color->rgba;
my $rpnexpr = <<'EOS';
# get the pixel
x y getp1 !pix
# check against the from_color
@pix red from_red eq
@pix green from_green eq
@pix blue from_blue eq
and and
# pick a result
to_red to_green to_blue rgb @pix ifp
EOS
# rpnexpr doesn't really support comments - remove them
$rpnexpr =~ s/^#.*\n//mg;
my %constants =
(
from_red => $from_red,
from_green => $from_green,
from_blue => $from_blue,
to_red => $to_red,
to_green => $to_green,
to_blue => $to_blue,
);
return Imager::transform2({ rpnexpr => $rpnexpr,
constants => \%constants },
$img);
}
__END__
=back
=head1 REVISION
$Revision$
=head1 AUTHOR
Tony Cook <tony@develop-help.com>
=head1 SEE ALSO
Imager, Imager::Engines, Imager::Color, Imager::Files
=cut