It all started with a note in our mailbox during corona: “Present yourself, your hobbies, via the front window of your house”.

I wanted to present something interactive, and I had a pen plotter available, so I decided to make a little site where neighbors could upload a picture and get a plotter drawing of it.

It had some attention, people tried it and were happily surprised with the result.

Next iteration

When we saw the call for makers for the Maker Faire at the office, I talked about this project and suggested we could use our AxiDraw to create something similar.

We decided to ditch the app and let people queue to let their picture get taken. You can take a look at the code yourself, but this is how it works:

• There is an Arduino micro hooked up to two buttons. The Arduino can act like a keyboard, so when you press a button, it will send a keystroke to the computer.
• The whole thing runs in Node.js using zx, it is like bash scripting, but then in node. I like it.
• When the command to take a picture is received, the native photo booth app is opened and a picture is taken. By running AppleScript from the Node.js script… An approach Wouter came up with, nice one!
• When the command to plot a new picture from the queue, the picture goes through a couple of steps:
  • The picture is cropped to a postcard-ratio, taking the position of one or more faces into account. Smartcrop
  • A Python script then transforms the cropped picture into a line drawing (SVG) Linedraw
  • The SVG gets simplified and optimized for plotting with vpype
• Finally, the optimized SVG is then plotted with the AxiDraw

Results

During the Maker Faire, we had a lot of visitors who were intrigued by the plotter and wanted to let their picture get drawn. We ran into a queue of multiple hours, so we had to refuse people at some point. The algorithm that translates a picture into a line drawing can bring surprising results now and then, but overall, people were happy with the result.