What Is a Fiducial Marker
And how they are used on computer vision.
If you see the image bellow, can you guess what are the card dimensions? Since you may have never seen such an object before, you will probably have difficulties guessing their dimensions. It could be as small as one millimeter or as large as 1 meter.
Now look again the next image. It becomes easier to guess the size, right? Simply putting another object, whose dimensions we know (or that we can easily guess), our brain can make an accurate estimation.
This known object is called a fiducial marker. In our case, a guitar pick whose dimensions we know (thanks, George Harrison).
A fiducial marker is an artificial landmark added to a scene to facilitate locating point correspondences between images. [1]
Basically, is anything that we add to a scene or an object that we can use as a reference or a measure point.
