image to 3d printable heightmap/lithophane
by Amanda Ghassaei
May 2013
detailed documentation at http://www.instructables.com/id/3D-Printed-Photograph/
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.