Extension:VisualMathCaptcha

VisualMathCaptcha extension gives your wiki a strong captcha with a math operation generated as image.

Installation
This extension requires you have GD module for PHP.

Download VisualMathExtension from here.

To install this extension, add the following to LocalSettings.php:

Configuration parameters

 * $wgVisualMathCaptchaItemMax : [int] max value (included) for each number in operation ; Defaulted to 9. Needs to be increased by at least a few orders of magnitude as a trivial single-digit challenge will let 10% of the spam through.


 * $wgVisualMathCaptchaItemNum : [int] count of number in generated operator; Defaulted to 2.


 * $wgVisualMathCaptchaOperators : [array] operators allowed for generation; Defaulted to { '+', '-' }.

With ConfirmEdit
This captcha can be used instead of standard captcha of ConfirmEdit extension. To do so :
 * 1) Open ConfirmEdit.php, in ConfirmEdit extension directory, and change $wgCaptchaClass value to VisualMathConfirmCaptcha</tt>.
 * 2) Add following line in LocalSettings.php, after content copied from provided file LocalSettings.part</tt> :

With Lockdown extension
VisualMathCaptcha uses a special page: SpecialPage:VisualMathCaptcha.

Add in LocalSettings.php

With CorporateContact

 * VisualMathCaptcha can be used with CorporateContact.