</p>
<p>class Captcha<br />
{<br />
protected $value;<br />
protected $image_name;<br />
<br />
public function __construct( $image_name )<br />
{<br />
$this->image_name = $image_name;<br />
}<br />
<br />
public static function createNumber( $length = 4 )<br />
{<br />
$num = "";<br />
for ( $i = 0; $i < $length; $i++ )<br />
{<br />
$r = mt_rand( 0, 9 );<br />
$num = $num.$r;<br />
}<br />
return $num;<br />
}<br />
<br />
public static function createString( $length = 4 )<br />
{<br />
$val = "";<br />
$values = "abcdefghijklmnopqrstuvwyz";<br />
for ( $i = 0; $i < $length; $i++ )<br />
{<br />
$r = mt_rand( 0, 24 );<br />
$val = $val.$values[$r];<br />
}<br />
return $val; <br />
}<br />
<br />
public function setValue( $value )<br />
{<br />
$this->value = $value;<br />
}<br />
<br />
public function getValue( )<br />
{<br />
return $this->value;<br />
}<br />
<br />
public function showImage( $channel = null )<br />
{<br />
$im = imageCreate( 160, 60 );<br />
$white = imagecolorallocate( $im, 255, 255, 255 );<br />
$black = imagecolorallocate( $im, 0, 0, 0 );<br />
<br />
$intensity = rand ( 200, 230 );<br />
<br />
if ( !$channel )<br />
{<br />
$channel = rand ( 1, 3 );<br />
}<br />
$ratio = rand ( 80, 100 );<br />
<br />
switch ( $channel )<br />
{<br />
case 1:<br />
$colorBgR = $intensity * $ratio / 100;<br />
$colorBgG = $intensity * ( 100 - $ratio ) / 100;<br />
$colorBgB = 0;<br />
<br />
for ( $i = 0; $i < 5; $i++ )<br />
{<br />
$shift = rand( 100 - ( $i+1)*3, 100 + ( $i+1)*3 );<br />
$new = $shift * $colorBgR / 100; <br />
<br />
$bgColors[] = iMagecolorallocate( $im, $new, $intensity-$new, 0 );<br />
}<br />
<br />
for ( $i = 0; $i < 3; $i++ )<br />
{<br />
$shift = rand( 100 - ( $i+1)*7, 100 + ( $i+1)*7 );<br />
$new = $shift * $colorBgR / 100; <br />
<br />
$bgColors[] = iMagecolorallocate( $im, $intensity-$new, $new, 0 );<br />
}<br />
break;<br />
<br />
case 2:<br />
$colorBgG = $intensity * $ratio / 100;<br />
$colorBgB = $intensity * ( 100 - $ratio ) / 100;<br />
$colorBgR = 0;<br />
<br />
for ( $i = 0; $i < 5; $i++ )<br />
{<br />
$shift = rand( 100 - ( $i+1)*3, 100 + ($i+1)*3 );<br />
$new = $shift * $colorBgR / 100; <br />
<br />
$bgColors[] = iMagecolorallocate( $im, 0, $new, $intensity-$new );<br />
}<br />
<br />
for ( $i = 0; $i < 3; $i++ )<br />
{<br />
$shift = rand( 100 - ( $i+1)*7, 100 + ( $i+1)*7 );<br />
$new = $shift * $colorBgR / 100; <br />
<br />
$bgColors[] = iMagecolorallocate( $im, 0 , $intensity-$new, $new );<br />
}<br />
<br />
case 3:<br />
$colorBgB = $intensity * $ratio / 100;<br />
$colorBgR = $intensity * ( 100 - $ratio ) / 100;<br />
$colorBgG = 0;<br />
<br />
for ( $i = 0; $i < 5; $i++ )<br />
{<br />
$shift = rand( 100 - ( $i+1)*3, 100 + ( $i+1)*3 );<br />
$new = $shift * $colorBgR / 100; <br />
<br />
$bgColors[] = iMagecolorallocate( $im, $intensity-$new, 0, $new );<br />
}<br />
<br />
for ( $i = 0; $i < 3; $i++ )<br />
{<br />
// to make it harder do symmetric range ^^ <br />
$shift = rand( 100 , 100 + ( $i+1)*20 );<br />
$new = $shift * $colorBgR / 100; <br />
<br />
$bgColors[] = iMagecolorallocate( $im, $new , 0, $intensity-$new );<br />
}<br />
break;<br />
}<br />
<br />
<br />
<br />
<br />
$bgColor = imagecolorallocate( $im, $colorBgR, $colorBgG, $colorBgB );<br />
<br />
<br />
for ( $i = 0; $i < strlen( $this->value ); $i++ )<br />
{<br />
$rotate = rand(-15, 15);<br />
<br />
$fontSize = rand(28, 36);<br />
imagettftext($im, $fontSize ,$rotate , 10+$i*31, 50, $black, "impact.ttf",$this->value[$i] ); <br />
}<br />
<br />
<br />
<br />
<br />
for ( $i = 0; $i < 160; $i++ )<br />
{<br />
for ( $j = 0; $j < 60; $j++ )<br />
{<br />
$pos = rand( 0, 7 );<br />
<br />
if ( imagecolorat( $im, $i, $j ) == $black )<br />
{<br />
$pos = rand( 6, 7 );<br />
<br />
<br />
<br />
imagesetpixel( $im, $i, $j, $bgColors[$pos] );<br />
}<br />
else<br />
{<br />
imagesetpixel( $im, $i, $j, $bgColors[$pos] );<br />
}<br />
}<br />
}<br />
<br />
imagejpeg( $im, "images/".$this->image_name.".jpg" );<br />
imagedestroy( $im );<br />
echo" <img src='/images/".$this->image_name.".jpg' style='border: 1px solid #000;' width='160' >";<br />
}<br />
}</p>
<p>
