I've found your solution. For the meager price tag of $1,575.00 (plus shipping) you can own your very own robot that will do it for you in a bout 20 minutes time!
Lumenlab has found a new use for their DIY CNC RoGR Gantry Robot... transferring your face to a pumpkin. All it takes is the robot, a photo, and open source software called EMC2. EMC2 comes with a program called "Image to gcode" that allows you to transition a gray scale indexed image to a depth map g-code for the RoGR to follow.
Very non traditional and probably not the most efficient use of a robot, but definitely interesting. See more about the carving and a video here.






