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#!perl

use strict;
use warnings;
use POSIX qw(floor);
use Imager;

my $width  = 250; # CAPTCHA ¤ÎÉý
my $height = 50;  # CAPTCHA ¤Î¹â¤µ

# 2 ¤Ä¤Î°ú¿ô¤Î´Ö¤ÎÀ°¿ô¤ò¥é¥ó¥À¥à¤ÇÊÖ¤¹
sub random {
    my($min, $max) = sort { $a <=> $b } @_;
    return floor($min + rand($max - $min + 1));
}

# 2 ¤Ä¤Î¿§¤Î´Ö¤Î¿§¤ò¥é¥ó¥À¥à¤ÇÊÖ¤¹
sub random_color {
    my($color_a, $color_b) = @_;
    my @rgb_a = map { hex $_ }
        $color_a =~ /^\#?([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})/i;
    my @rgb_b = map { hex $_ }
        $color_b =~ /^\#?([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})/i;
    my $r = random($rgb_a[0], $rgb_b[0]);
    my $g = random($rgb_a[1], $rgb_b[1]);
    my $b = random($rgb_a[2], $rgb_b[2]);
    return sprintf '#%02x%02x%02x', $r, $g, $b;
}

# CAPTCHA ¤òºî¤ë
my $imager = Imager->new(xsize => $width, ysize => $height);
$imager->box(filled => 1, color => random_color('#cccccc', '#ffffff'));

¤È¤ê¤¢¤¨¤º¡¢¤³¤ó¤Ê¤ó¤·¤Æ¤ª¤¤¤Æ¡¢

$imager->write(file => 'captcha.png', type => 'png');

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¤¢¡¢¤Á¤Ê¤ß¤Ë¡¢¤³¤ì¤Ï¼Â¹Ô¤¹¤ë¤¿¤Ó¤Ë¿§¤¬¥³¥í¥³¥í¤«¤ï¤ê¤Þ¤¹¡£

¤Ç¤Ï¡¢¤³¤³¤Ë 200 ¡Á 300 ¸ÄÄøÅ٤Υ֥ĥ֥Ĥò²Ã¤¨¤Æ¡¢¥³¥ó¥Ë¥ã¥¯¤Ã¤Ý¤¯¤·¤Þ¤¹¡£

for (1 .. random(200, 300)) {
    $imager->setpixel(
        x     => random(0, $width - 1),
        y     => random(0, $height - 1),
        color => random_color('#000000', '#666666'),
    );
}

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$imager->filter(type => 'gaussian', stddev => 0.5);

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¼¡¤ËŬÅö¤ÊÀþ¤ò 3 ¡Á 5 ËÜÄøÅÙÆþ¤ì¤Þ¤¹¡£

for (1 .. random(3, 5)) {
    $imager->line(
        color => random_color('#000000', '#666666'),
        x1    => random(0, $width - 1),
        y1    => random(0, $height - 1),
        x2    => random(0, $width - 1),
        y2    => random(0, $height - 1),
        aa    => 1,
    );
}

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¼¡¤Ë¤¤¤è¤¤¤èʸ»ú¤òÆþ¤ì¤ë¤Î¤Ç¤¹¤¬¡¢Å¬Åö¤Êʸ»ú¤òÊÖ¤¹´Ø¿ô¤òºî¤ê¤Þ¤¹¡£
¤Ò¤é¤¬¤Ê¤È¥«¥¿¥«¥Ê¤òÊÖ¤¹¤è¤¦¤Ë¤·¤Þ¤·¤ç¤¦¡£

use List::Util qw(shuffle);
use utf8;

sub random_char {
    my($min, $max) = @_;
    my $length = random($min, $max);
    my @chr = ();
    push @chr, map { chr($_) } (ord('¤¢') .. ord('¤ó'));
    push @chr, map { chr($_) } (ord('¥¢') .. ord('¥ó'));
    return join '', (shuffle(@chr))[0 .. $length - 1];
}

¤³¤ì¤Ç¡¢random_char()¤ò¸Æ¤Ó½Ð¤¹¤È¡¢»ØÄꤷ¤¿Ê¸»ú¿ôÆâ¤ÇŬÅö¤ËÁȤ߹ç¤ï¤»¤¿¤Ò¤é¤¬¤Ê¤È¥«¥¿¥«¥Ê¤òÁȤ߹ç¤ï¤»¤¿Ã±¸ì¤¬ÊÖ¤ê¤Þ¤¹¡£

¼¡¤Ë¥Õ¥©¥ó¥È¤Î¥ª¥Ö¥¸¥§¥¯¥È¤òºî¤ê¤Þ¤¹¡£

use Imager::Font;

my @fonts = map { sprintf '/path/to/%s.ttc', $_ } qw(msgothic msmincho);

my $font = Imager::Font->new(
    file => (shuffle(@fonts))[0],
    size => 35,
    aa   => 1,
    type => 'ft2',
);

my $word;
my $bbox;
while (1) {
    $word = random_char(5, 8);
    $bbox = $font->bounding_box(string => $word);
    next if $bbox->total_width >= $width;
    last;
}

5 ¡Á 8 ʸ»úÄøÅ٤Υé¥ó¥À¥à¤Êʸ»ú¤òºî¤ê¤Þ¤¹¤¬¡¢Ê¸»ú¤òÀ¸À®¤·¤¿»þ¤Ë¡¢Ê¸»ú¤Îɽ¼¨Éý¤¬Á´ÂÎÏȤÎÂ礭¤µ¤òĶ¤¨¤Ê¤¤¤è¤¦¤Ë¡¢¥Ï¥ß½Ð¤¿¾ì¹ç¤Ï¤â¤¦°ìÅÙÊ̤Îñ¸ì¤òºî¤ë¤è¤¦¤Ë¤·¤Þ¤¹¡£

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use Imager::Matrix2d;

my $x = floor(($width - $bbox->total_width) / 2);
for my $char (split //, $word) {
    my $bbox = $font->bounding_box(string => $char);
    # ·Ú¤¯¥Ò¥Í¥ê¤ò²Ã¤¨¤Þ¤¹
    my $matrix = Imager::Matrix2d->shear(
        x => (random(-3, 3) / 10),
        y => (random(-3, 3) / 10),
    );
    $font->transform(matrix => $matrix);
    # ¹â¤µ¤Ï¥é¥ó¥À¥à¤ËÇÛÃÖ¤·¤Þ¤¹
    my $y = random(10, floor($height - $bbox->font_height) * 2 - 10);
    $imager->string(
        align  => 0,
        x      => $x,
        y      => $y,
        halign => 'center',
        string => $char,
        font   => $font,
        color  => random_color('#000000', '#666666'),
    );
    $x += $bbox->total_width;
}

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for (1 .. random(10, 15)) {
    my $angle = random(0, 360);
    my $x = random(0, $width);
    my $y = random(0, $height);
    my $radius = random(0, $width - $x);
    $imager->arc(
        color => random_color('#000000', '#666666'),
        x     => $x,
        y     => $y,
        r     => $radius,
        d1    => $angle,
        d2    => $angle + 1,
        aa    => 1,
    );
}

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º£²ó¤Ï Imager ¤ò»È¤Ã¤Æ CAPTCHA Ū¤Ê¤â¤Î¤ò´Êñ¤Ëºî¤ë¼ê½ç¤Î¾Ò²ð¤Ë¤«¤³¤Ä¤±¡¢¤Ê¤ó¤È¤Ê¤¯°ìÅÙºî¤Ã¤Æ¤ß¤¿¤«¤Ã¤¿ÆüËܸì CAPTCHA ¤òºî¤Ã¤Æ¤ß¤Þ¤·¤¿¡£

¼ÂºÝ¤Ë¤³¤ì¤ò CAPTCHA ¤È¤·¤Æ¥Õ¥©¡¼¥à¤ÇÍøÍѤ¹¤ë¾ì¹ç¤Ï¡¢²èÁü¤ò¤É¤Î¤è¤¦¤Ë½ÐÎϤ¹¤ë¤« (¥Õ¥¡¥¤¥ë¤òÅǤ­½Ð¤¹¤«¡¢WAF ¤ÎÃ椫¤é¤½¤Î¤Þ¤Þ²èÁü¥Ç¡¼¥¿¤ò½ÐÎϤ¹¤ë¤Î¤«¤È¤«¡¢¥­¥ã¥Ã¥·¥å¤È¤«¤É¤¦¤¹¤ë¤Î¤«¤È¤«) ¤ä¡¢ËÜÅö¤ËÆüËܸì¤Ç¤¤¤¤¤Î¤« (¿ô»ú¤À¤±¤Ë¤¹¤ë¤È¤«¡¢±Ñ¸ì¤Ë¤¹¤ë¤Ê¤é¥é¥ó¥À¥à¤Ë¤¹¤ë¤Î¤«¤È¤«¡¢/usr/share/dict/words Åù¤«¤éŬÅö¤Êñ¸ì¤ò°ú¤ÃÄ¥¤Ã¤Æ¤¯¤ë¤è¤¦¤Ë¤¹¤ë¤Î¤«¤È¤«) ¤ä¡¢Ê¶¤é¤ï¤·¤¤Ê¸»ú (Ù¹²»¤äÂ¥²»¡¢ÂùÅÀ¤äȾÂùÅÀ) ¤ò´Þ¤á¤ë¤Î¤«¡¢¥Õ¥©¡¼¥à¤«¤é submit ¤µ¤ì¤¿Ê¸»ú¤Î validation ÊýË¡¤ò¤É¤¦¤¹¤ë¤Î¤«¡¢Åù¡¹¤Ë¤Ä¤¤¤Æ¹Íθ¤¹¤ëɬÍפ¬¤¢¤ê¡¢¤³¤ì¤òɽ¼¨¤¹¤ë¤À¤±¤ÇºÑ¤àÌäÂê¤Ç¤Ï¤¢¤ê¤Þ¤»¤ó¤¬¡¢¤³¤ì¤ò¸µ¤Ë Imager ¤ò»È¤Ã¤Æ¤¢¤Ê¤¿¹¥¤ß¤Î CAPTCHA ¤òºî¤é¤ì¤Æ¤ß¤Æ¤Ï¤¤¤«¤¬¤Ç¤·¤ç¤¦¤«¡£

¤½¤ì¤Ç¤Ïº£Ç¯¤â¤è¤í¤·¤¯¤ª´ê¤¤¤·¤Þ¤¹¡£

#!perl

use strict;
use warnings;
use utf8;
use POSIX qw(floor);
use Imager;
use Imager::Font;
use Imager::Matrix2d;
use List::Util qw(shuffle);

my $width  = 250; # CAPTCHA ¤ÎÉý
my $height = 50;  # CAPTCHA ¤Î¹â¤µ

# 2 ¤Ä¤Î°ú¿ô¤Î´Ö¤ÎÀ°¿ô¤ò¥é¥ó¥À¥à¤ÇÊÖ¤¹
sub random {
    my($min, $max) = sort { $a <=> $b } @_;
    return floor($min + rand($max - $min + 1));
}

# 2 ¤Ä¤Î¿§¤Î´Ö¤Î¿§¤ò¥é¥ó¥À¥à¤ÇÊÖ¤¹
sub random_color {
    my($color_a, $color_b) = @_;
    my @rgb_a = map { hex $_ }
        $color_a =~ /^\#?([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})/i;
    my @rgb_b = map { hex $_ }
        $color_b =~ /^\#?([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})/i;
    my $r = random($rgb_a[0], $rgb_b[0]);
    my $g = random($rgb_a[1], $rgb_b[1]);
    my $b = random($rgb_a[2], $rgb_b[2]);
    return sprintf '#%02x%02x%02x', $r, $g, $b;
}

# CAPTCHA ¤òºî¤ë
my $imager = Imager->new(xsize => $width, ysize => $height);
$imager->box(filled => 1, color => random_color('#cccccc', '#ffffff'));

for (1 .. random(200, 300)) {
    $imager->setpixel(
        x     => random(0, $width - 1),
        y     => random(0, $height - 1),
        color => random_color('#000000', '#666666'),
    );
}

$imager->filter(type => 'gaussian', stddev => 0.5);

for (1 .. random(3, 5)) {
    $imager->line(
        color => random_color('#000000', '#666666'),
        x1    => random(0, $width - 1),
        y1    => random(0, $height - 1),
        x2    => random(0, $width - 1),
        y2    => random(0, $height - 1),
        aa    => 1,
    );
}

sub random_char {
    my($min, $max) = @_;
    my $length = random($min, $max);
    my @chr = ();
    push @chr, map { chr($_) } (ord('¤¢') .. ord('¤ó'));
    push @chr, map { chr($_) } (ord('¥¢') .. ord('¥ó'));
    return join '', (shuffle(@chr))[0 .. $length - 1];
}

my @fonts = map { sprintf '/path/to/%s.ttc', $_ } qw(msgothic msmincho);

my $font = Imager::Font->new(
    file => (shuffle(@fonts))[0],
    size => 35,
    aa   => 1,
    type => 'ft2',
);

my $word;
my $bbox;
while (1) {
    $word = random_char(5, 10);
    $bbox = $font->bounding_box(string => $word);
    next if $bbox->total_width >= $width;
    last;
}

my $x = floor(($width - $bbox->total_width) / 2);
for my $char (split //, $word) {
    my $bbox = $font->bounding_box(string => $char);
    # ·Ú¤¯¥Ò¥Í¥ê¤ò²Ã¤¨¤Þ¤¹
    my $matrix = Imager::Matrix2d->shear(
        x => (random(-3, 3) / 10),
        y => (random(-3, 3) / 10),
    );
    $font->transform(matrix => $matrix);
    # ¹â¤µ¤Ï¥é¥ó¥À¥à¤ËÇÛÃÖ¤·¤Þ¤¹
    my $y = random(10, floor($height - $bbox->font_height) * 2 - 10);
    $imager->string(
        align  => 0,
        x      => $x,
        y      => $y,
        halign => 'center',
        string => $char,
        font   => $font,
        color  => random_color('#000000', '#666666'),
    );
    $x += $bbox->total_width;
}

for (1 .. random(10, 15)) {
    my $angle = random(0, 360);
    my $x = random(0, $width);
    my $y = random(0, $height);
    my $radius = random(0, $width - $x);
    $imager->arc(
        color => random_color('#000000', '#666666'),
        x     => $x,
        y     => $y,
        r     => $radius,
        d1    => $angle,
        d2    => $angle + 1,
        aa    => 1,
    );
}

$imager->write(file => 'captcha.png', type => 'png');