Performing Camera Calibration Checkered board pattern

Question

I am performing Camera Calibration and I was wondering whether it matters if the Checkered board pattern being used is symmetrical or asymmetrical.

Does it make any difference?

Thanks;

Answer 1

A symmetric checkerboard pattern is ambiguous: you cannot tell if it is rotated 90 degrees or 180 degrees. Asymmetric pattern does not have this ambiguity. If your checkerboard is non-square, then you can tell if it is rotated 90 degrees. If one of its sides has an even number of squares, and the other has an odd number of squares, then you can tell if it is upside down (rotated 180 degrees).

Answer 2

A concern with a symmetric checkerboard is that you cannot use it to compute absolute poses w.r.t. the camera if there is a possibility of occlusions - since you cannot tell which corner is which if they aren't all visible. There are nonsymmetrical patterns that can deal with this issue as well. My favorite is Matsunaga and Kanatani's "2D barcode" one, which uses sequences of square lengths with unique crossratios. See the paper here