When I was at the Cirque des Sciences in Luxembourg (September
2007), I saw
Erik's XY plotter
in action, and I thought I should make my own portrayer robot.
During a dinner in Luxembourg,
Claude Baumann explained to me how to
transform a raster image (composed by pixels) into a vector
is his tutorial about vectorization.
I started building a cartesian plotter like the one seen in
Luxembourg, based on the LEGO
Technic Control Center plotter 8094.
That prototype was really precise, allowing 0.1mm resolution.
I showed the first prototype of the portrayer at the Festival of
Creativity (Florence) in October 2008. In two days the robot portrayed more
than 170 people!
The photos were taken by a webcam on a white background, to help
edge extraction. The best illumination is diffuse white, to
avoid sharp shadows on the faces.