I'm sure the end result is great, but I cannot get it to work after 30 minutes of trying. I have created about 20 Joomla sites of varying complexity, so I know what I'm doing. I instaleld the component, uploaded patch, saved config, made sure I had the correct versions of plugins, the plugin is enabled, I have registrations set to Yes - I have followed directions (what little there are) perfectly and still no captcha on registration. Since I already "patched" my core Joomla files, I feel like I'm trapped with this component so I'll have to sift through the forums of their site to find out why this is not working. Could be user error, but I'm not the first to say that this has terrible installation instructions.
Owner's replyInstallation instructions are quite explanatory, you just have to go through.
http://wiki.waltercedric.com/index.php?title=SecurityImages5.0.X