Fiducial

From Wikipedia, the free encyclopedia

• In statistics, fiducial inference is a form of interval estimation developed by R.A. Fisher in connection with the Behrens-Fisher problem.

• In physics, 3D computer graphics and photography, fiducials are reference points: fixed points or lines within a scene to which other objects can be related or against which objects can be measured. Cameras outfitted with reseau plates produce these reference marks (also called reseau crosses) and are commonly used by NASA.[1]

• In applications of augmented reality or virtual reality, fiducials are often manually applied to objects in the scenery to recognize these objects in images of the scenery. For example, to track some object, a light emitting diode can be applied to it. With the knowledge of the color of the emitted light, the object can easily be identified in the picture.

• In printed circuit board (PCB) design, fiducial marks, also known as circuit pattern recognition marks, allow automated assembly equipment to accurately locate and place parts on boards. These equipment locate the circuit pattern by providing common measurable points. They are usually made by leaving a spot of the board bare with a bare copper-, nickel-, or solder-coated dot inside.