Make: Volume 90

FIDUCIAL MARKERS

The term fiducial comes from the Latin

fiducia, to trust. Since our ability to trust

the orientation and scale of items in

images frequently relies on a reference of

some kind, these are often called fiducial

markers. These markers vary from simple

comparisons of scale, like including a ruler

or coin in a photo, to the highly precise

Réseau crosses seen in NASA images from

the moon landings. QR codes often have

a square with an outline in three corners

to provide orientation. Multicolor printing

systems typically rely on registration marks

to align different color runs. Pick-and-place

robots rely on circuit pattern recognition ...