este es parte del codigo fuente:
<?PHP
#############################################
# Project: HumanCheck 2.1
# file: humancheck_config.php
# company: SmiledSoft.com (SmiledSoft.com)
# author: Yuriy Horobey (
[email protected])
# purpose: outputs picture with secret code
# date: 24.08.2004
#
#############################################
error_reporting(85);//serious error only
require(dirname(__FILE__)."/humancheck_config.php");
$sid=trim($HTTP_GET_VARS["sid"]);
session_id($sid);
session_start();
$noautomationcode = $HTTP_SESSION_VARS["noautomationcode"];
$img_path = dirname(__FILE__)."/$config_back_image";
$img = ImageCreateFromJpeg($img_path );
$img_size = getimagesize($img_path );
$fw = imagefontwidth ( $config_font );
$fh = imagefontheight ( $config_font );
$x = ($img_size[0] - strlen($noautomationcode) * $fw )/2;
$y = ($img_size[1] - $fh) / 2; // middle of the code string will be in middle of the background image
$color = imagecolorallocate($img,
hexdec(substr($config_code_color,1,2)),
hexdec(substr($config_code_color,3,2)),
hexdec(substr($config_code_color,5,2))
);
imagestring ( $img, $config_font, $x, $y, $noautomationcode, $color);
header("Content-Type: image/jpeg");
imagejpeg($img);
?>