This is the new generation IceCaptcha plugin. The Anti-Spam security system misses no bots and does not disturb a human being.
You can indicate optional circle radius in the plugin settings inside your admin panel. The default size is set to 10.
Scale is used to change the size of the captcha itself (the picture). Let’s say you’ve got some specific commentaries’ form design with no room for the standard “big” captcha, in this case you can adjust the size of the captcha and make it smaller (e.g. 0.8) to have it perfectly fitting your design.
That’s quite simple, 1 constitutes 100% of the standard captcha size. WordPress uses 0.92, which corresponds to the 92%. If you need a bigger captcha you are welcome to set any value larger than 1, e.g., 1.2 or 1.33 (120% or 133% correspondingly), if you want a smaller one, than it will work vice versa, e.g - 0.65 (65%).