Drawing pictures using an etch a sketch, motors and python.
Detailed writeup available here: http://sunnybala.com/2018/09/10/python-etch-a-sketch.html
I did the image analysis (EtchASketch.py) on my PC. It generates a path in the Paths/ folder. I then ran pictureDraw.py (which imports stepperMotor.py) on my raspberry pi to actually draw the images. You'll need to adjust these files to calibrate for your specific build.
A few sample images and their outputs are pre-populated. I used sigma parameters between .33 and 1.