Customizable stereographic projection flat

Basically the same as http://www.thingiverse.com/thing:295281 but this time the bottom is flattened so it is easier to print.
The customizer takes 75x75 images, but you must be very careful that no diagonally touching pixels occur, as 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/