xF1 Add-on Photo CAPTCHA 0.0.2

This is a simple CAPTCHA based on ASIRRA project's idea.
User is presented with multiple images of different objects and must select images of correct type, such as dogs or cats.

Its a good choice for your forum because its not a standard CAPTCHA, so spam bots can't solve it yet, its easy to customize and its very friendly to visitors.

Features:

• Works without JavaScript.
• Image collections can be easily customized.
• If you have successfully completed CAPTCHA, but failed to fill in some other registration form field, images will be automatically selected, so you won't have to fill in twice.

Built-in limitations that are currently not configurable, designed to prevent bots from just guessing answers:

• Each user can only see 3 sets of images. When loading registration page for 4th+ time he'll see one of previously shown image sets.
• Each user has only 5 attempts to complete captcha. If he fails to complete captcha 5 or more times, all further attempts will result in fail even if answer is correct. Attempts when no images were selected by user do not count towards number of failures.

Additional notes:

• Current version is not translatable yet. All text is hardcoded.
• There is no admin interface for managing collections of images yet.

You can see it live at my support forum: http://www.artodia.com/login/login


How to add/remove/customize image collections:
Go to directory library/PhotoCaptcha/Collections/. In that directory you will find sub-directories with collections of images. Add/remove images, edit collection.json (text file). Each image should be 200x160 pixels in jpg, png or gif format.

Images in default collections are mostly from random websites. Some might be copyrighted. I'll replace them with images that can be distributed later.