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Revision: 34084
at October 17, 2010 02:33 by stz184
Initial Code 
session_start();
header("Content-type: image/png");
$width = 120;
$height = 30;
$im = @imagecreate($width, $height)
    or die("Cannot Initialize new GD image stream");
imagecolorallocate($im, 247, 250, 233);
$noise_color = imagecolorallocate($im, 253, 175, 90);
	for( $i=0; $i<($width*$height)/3; $i++ ) {
         imagefilledellipse($im, mt_rand(0,$width), mt_rand(0,$height), 1, 1, $noise_color);
      }
      /* generate random lines in background */
      for( $i=0; $i<($width*$height)/120; $i++ ) {
         imageline($im, mt_rand(0,$width), mt_rand(0,$height), mt_rand(0,$width), mt_rand(0,$height), $noise_color);
      }
$text_color = imagecolorallocate($im, 175, 102, 43);


$action = array('+', '*', '-');
shuffle($action);
if($action[0] == '+') {
	$a = rand(1, 9);
	$b = rand(1, 9);
	$_SESSION['code'] = $a + $b;
}
elseif($action[0] == '*') {
	$a = rand(1, 9);
	$b = rand(1, 9);
	$_SESSION['code'] = $a * $b;
}
elseif($action[0] == '-') {
	$b = rand(1, 9);
	$c = $b+1;
	$a = rand($c, 9);
	
	$_SESSION['code'] = $a - $b;
}

$text = $a.$action[0].$b;

for($j = 0; $j < strlen($text); $j++) {
	$angle = rand(-20, 20);
	imagettftext($im, 18, $angle, 29+($j*23), (18+(($height-18)/2)), $text_color, './WC_Wunderbach_Rough.ttf', $text[$j] );
}
imagepng($im);
imagedestroy($im);

//usage : save this snippet as captcha.php file and use it that
//point it as image source 
//<img src="captcha.php" />
//to check is it passed correctly, do following
//if(isset($_SESSION['code']) && ($_POST['captcha'] == $_SESSION['code'])) 
//its needed to check is $_SESSION['code'] is set, because if somebody block
//the image loading, the check ($_POST['captcha'] == $_SESSION['code']) will 
//return false positive if the form is sent with empty captcha field
Initial URL 

                                

                                                            

                                    

                                        

                                        Initial Description
                                        

                                    

                                    
Save this snippet as .php file and use it as image source.
This captcha code shows random arithmetic's questions.
You can download needed font from http://www.1001fonts.com/font_details.html?font_id=2939

                                

                                                            

                                    

                                        

                                        Initial Title
                                        

                                    

                                    
Captcha with arithmetic's questions

                                

                                                            

                                    

                                        

                                        Initial Tags
                                        

                                    

                                    

                                

                                                            

                                    

                                        

                                        Initial Language
                                        

                                    

                                    
PHP