<?php session_start(); ////////////////////////////////////////// // Abzetdin Z. Adamov // Copyrights © 2008 // All rights reserved. // // Last modified 11/20/2010 // This program is open-source PHP Captcha, which helps to make sure // that only humans perform certain actions with your website, // protecting it from spam bots (software). // Requires: PHP and GD module ////////////////////////////////////////// header("Content-type:image/gif"); $captcha_length = 4; // the number of symbols in captcha $font_name = 'alba.ttf'; // the font $font_size = 26; // the size $captcha_angle = rand(-8, 8);; // the angle of captcha string // Depending on what kind of symbols (Numbers, Chars, Chars and Numbers) you would like to see on your captcha, leave oppropriate lines and remove others... //--Random Numbers $numbs = range ('0', '9'); shuffle($numbs); $captcha_str = implode(array_slice($numbs, 0, $captcha_length)); //--Random Chars $chars = range ('A', 'Z'); shuffle($chars); $captcha_str = implode(array_slice($chars, 0, $captcha_length)); //--Random Chars and Numbers $chars = range ('A', 'Z'); $numbs = range ('0', '9'); $symbs = array_merge($chars, $numbs); shuffle($symbs); $captcha_str = implode(array_slice($symbs, 0, $captcha_length)); // Define Session with the value of captcha string $_SESSION['captch'] = "$captcha_str"; // Create captcha image $backgroundimage = "images/security_background.gif"; $im=imagecreatefromgif($backgroundimage); $color = imagecolorallocate($im, rand(0,255), rand(0,255), rand(0,255)); $bbox = imagettfbbox ($font_size, $captcha_angle, $font_name, $captcha_str); $captcha_width = $bbox[2] - $bbox[0]; $x -= $captcha_width / 2; imagettftext($im, $font_size, $captcha_angle, 50+$x, 30, $color, $font_name, $captcha_str); imagegif($im); imagedestroy($im); ?>