Basically the same as http://www.thingiverse.com/thing:295281 but the form is no sphere but is flattened to some kind of mushroom shape. The customizer takes 75x75 images, but you must be very careful that no diagonally touching pixels occur, as even a single one will prevent generation of the stl. [Edit] Minor bug with the outer borders fixed. If you need bigger versions you can do it locally with OpenScad and this script: http://jsfiddle.net/threonin/3j2c2pwe/