官方网站：http://www.phpcaptcha.org/
下载地址：http://www.phpcaptcha.org/download/
原文地址：http://www.21andy.com/blog/20100417/1886.html
Securimage 使用方法：
验证码图片：
<img id="captcha" src="/securimage/securimage_show.php" alt="CAPTCHA Image" />
验证码文本框：
<input type="text" name="captcha_code" size="10" maxlength="6" />
看不清验证码：
<a href="#" rel="nofollow" target="_blank">Reload Image</a>
原文地址：http://www.21andy.com/blog/20100417/1886.html
后端PHP验证：
<?php
session_start();
include_once $_SERVER['DOCUMENT_ROOT'] . '/securimage/securimage.php';
$securimage = new Securimage();
if ($securimage->check($_POST['captcha_code']) == false) {
// the code was incorrect
// handle the error accordingly with your other error checking
// or you can do something really basic like this
die('The code you entered was incorrect. Go back and try again.');
}
session_start();
include_once $_SERVER['DOCUMENT_ROOT'] . '/securimage/securimage.php';
$securimage = new Securimage();
if ($securimage->check($_POST['captcha_code']) == false) {
// the code was incorrect
// handle the error accordingly with your other error checking
// or you can do something really basic like this
die('The code you entered was incorrect. Go back and try again.');
}
Securimage 类属性：
$img->image_width = 275;
$securimage->image_height = 90;
$securimage->perturbation = 0.9; // 1.0 = high distortion, higher numbers = more distortion
$securimage->image_bg_color = new Securimage_Color("#0099CC");
$securimage->text_color = new Securimage_Color("#EAEAEA");
$securimage->text_transparency_percentage = 65; // 100 = completely transparent
$securimage->num_lines = 8;
$securimage->line_color = new Securimage_Color("#0000CC");
$securimage->signature_color = new Securimage_Color(rand(0, 64), rand(64, 128), rand(128, 255));
$securimage->image_type = SI_IMAGE_PNG;
$securimage->show('backgrounds/bg5.jpg')
$securimage->image_height = 90;
$securimage->perturbation = 0.9; // 1.0 = high distortion, higher numbers = more distortion
$securimage->image_bg_color = new Securimage_Color("#0099CC");
$securimage->text_color = new Securimage_Color("#EAEAEA");
$securimage->text_transparency_percentage = 65; // 100 = completely transparent
$securimage->num_lines = 8;
$securimage->line_color = new Securimage_Color("#0000CC");
$securimage->signature_color = new Securimage_Color(rand(0, 64), rand(64, 128), rand(128, 255));
$securimage->image_type = SI_IMAGE_PNG;
$securimage->show('backgrounds/bg5.jpg')
Securimage AJAX 完整示例
AJAX 前端HTML：
<html>
<head>
<title>PHP Captcha with Ajax</title>
<script type="text/javascript" src="prototype.js"></script>
<script type="text/javascript">
<!--
function processForm()
{
$('submit').disabled = true;
$('submit').value = "Processing. Please Wait...";
$('contact_form').request({
onSuccess: function(transport)
{
if(transport.responseText.match(/^OK/) != null) {
alert('Your message has been sent!');
$('contact_form').reset();
} else {
alert(transport.responseText);
}
$('submit').value = 'Send Message';
$('submit').disabled = false;
}
});
return false;
}
-->
</script>
</head>
<body>
<form id="contact_form" action="process.php" method="post" onsubmit="return processForm()">
<div style="float: left; 100px">Your name:</div>
<div style="float: left"><input type="text" name="sender_name" size="20" /></div>
<div style="clear: both"></div>
<div style="float: left; 100px">Email:</div>
<div style="float: left"><input type="text" name="sender_email" size="30" /></div>
<div style="clear: both"></div>
<div style="float: left; 100px">Message:</div>
<div style="float: left"><textarea name="message" rows="4" cols="30"></textarea></div>
<div style="clear: both"></div>
<div style="float: left; 100px">Security Image:</div>
<div style="float: left"><img src="securimage/securimage_show.php" alt="CAPTCHA Image" /></div>
<div style="clear: both"></div>
<div style="float: left; 100px">Security Code:</div>
<div style="float: left"><input type="text" name="code" size="8" /></div>
<div style="clear: both"></div>
<div style="float: left; 100px"> </div>
<div style="float: left"><input id="submit" type="submit" value="Send Message" /></div>
<div style="clear: both"></div>
</form>
</body>
</html>
<head>
<title>PHP Captcha with Ajax</title>
<script type="text/javascript" src="prototype.js"></script>
<script type="text/javascript">
<!--
function processForm()
{
$('submit').disabled = true;
$('submit').value = "Processing. Please Wait...";
$('contact_form').request({
onSuccess: function(transport)
{
if(transport.responseText.match(/^OK/) != null) {
alert('Your message has been sent!');
$('contact_form').reset();
} else {
alert(transport.responseText);
}
$('submit').value = 'Send Message';
$('submit').disabled = false;
}
});
return false;
}
-->
</script>
</head>
<body>
<form id="contact_form" action="process.php" method="post" onsubmit="return processForm()">
<div style="float: left; 100px">Your name:</div>
<div style="float: left"><input type="text" name="sender_name" size="20" /></div>
<div style="clear: both"></div>
<div style="float: left; 100px">Email:</div>
<div style="float: left"><input type="text" name="sender_email" size="30" /></div>
<div style="clear: both"></div>
<div style="float: left; 100px">Message:</div>
<div style="float: left"><textarea name="message" rows="4" cols="30"></textarea></div>
<div style="clear: both"></div>
<div style="float: left; 100px">Security Image:</div>
<div style="float: left"><img src="securimage/securimage_show.php" alt="CAPTCHA Image" /></div>
<div style="clear: both"></div>
<div style="float: left; 100px">Security Code:</div>
<div style="float: left"><input type="text" name="code" size="8" /></div>
<div style="clear: both"></div>
<div style="float: left; 100px"> </div>
<div style="float: left"><input id="submit" type="submit" value="Send Message" /></div>
<div style="clear: both"></div>
</form>
</body>
</html>
AJAX 后端PHP：
下载: process.php
<?php
/**
* Securimage with AJAX
*
* Author: Drew Phillips (www.phpcaptcha.org)
*
* This code is released to the public domain.
*
*/
$your_email = 'you@example.com'; // Email to send message to
if ($_SERVER['REQUEST_METHOD'] != 'POST') exit; // Quit if it is not a form post
// quick way clean up incoming fields
foreach($_POST as $key => $value) $_POST[$key] = urldecode(trim($value));
// get form data into shorter variables
// each $_POST variable is named based on the form field's id value
$name = $_POST['sender_name'];
$email = $_POST['sender_email'];
$message = $_POST['message'];
$code = $_POST['code'];
$errors = array(); // array of errors
// basic validation
if ($name == '') {
$errors[] = "Please enter your name";
}
if ($email == '') {
$errors[] = "Please enter your email address";
} else if (strpos($email, '@') === false) {
$errors[] = "Please enter a valid email address";
}
if ($message == '') {
$errors[] = "Please enter a message to send";
}
if (sizeof($errors) == 0) {
// only check the code if there are no other errors
require_once 'securimage/securimage.php';
$img = new Securimage;
if ($img->check($code) == false) {
$errors[] = "Incorrect security code entered";
} // if the code checked is correct, it is destroyed to prevent re-use
}
if (sizeof($errors) > 0) {
// if errors, send the error message
$str = implode("\n", $errors);
die("There was an error with your submission! Please correct the following:\n\n" . $str);
}
$time = date('r');
$body = <<<EOD
Hi!
A message was sent to you from $name on $time.
Here is their message:
$message
EOD;
// send email
mail($your_email, "Contact Form Sent", $body, "From: $your_email\r\nReply-To: $email\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nMIME-Version: 1.0");
die('OK'); // send success indicator
?>
/**
* Securimage with AJAX
*
* Author: Drew Phillips (www.phpcaptcha.org)
*
* This code is released to the public domain.
*
*/
$your_email = 'you@example.com'; // Email to send message to
if ($_SERVER['REQUEST_METHOD'] != 'POST') exit; // Quit if it is not a form post
// quick way clean up incoming fields
foreach($_POST as $key => $value) $_POST[$key] = urldecode(trim($value));
// get form data into shorter variables
// each $_POST variable is named based on the form field's id value
$name = $_POST['sender_name'];
$email = $_POST['sender_email'];
$message = $_POST['message'];
$code = $_POST['code'];
$errors = array(); // array of errors
// basic validation
if ($name == '') {
$errors[] = "Please enter your name";
}
if ($email == '') {
$errors[] = "Please enter your email address";
} else if (strpos($email, '@') === false) {
$errors[] = "Please enter a valid email address";
}
if ($message == '') {
$errors[] = "Please enter a message to send";
}
if (sizeof($errors) == 0) {
// only check the code if there are no other errors
require_once 'securimage/securimage.php';
$img = new Securimage;
if ($img->check($code) == false) {
$errors[] = "Incorrect security code entered";
} // if the code checked is correct, it is destroyed to prevent re-use
}
if (sizeof($errors) > 0) {
// if errors, send the error message
$str = implode("\n", $errors);
die("There was an error with your submission! Please correct the following:\n\n" . $str);
}
$time = date('r');
$body = <<<EOD
Hi!
A message was sent to you from $name on $time.
Here is their message:
$message
EOD;
// send email
mail($your_email, "Contact Form Sent", $body, "From: $your_email\r\nReply-To: $email\r\nContent-Type: text/plain; charset=ISO-8859-1\r\nMIME-Version: 1.0");
die('OK'); // send success indicator
?>
更详细的文档请看官方网站