image_captcha will pull the images out of a user-defined directory and obfuscate them before rendering them to the screen. It will then allow the user to select the correct image via a select box or a radio button. This also allows the admin to choose the number of random words or filenames that will appear in the select box or radio field.
Thumbnail support is available, in which missing thumbs are automatically generated from larger images and then displayed. Audio support is also provided for the visually impaired.