Design of fiducials for accurate registration using machine vision
Chinmoy B. Bose, Jacob Amir · IEEE Transactions on Pattern Analysis and Machine Intelligence · 1990
The effect of the shape and size of a standard feature (fiducial) on the positional accuracy of the centroid in machine-vision applications is studied. It is shown that a circular fiducial provides superior subpixel registration accuracy among the fiducial shapes typically used today.>