Camera calibrations are often done with a chess board pattern, as it shows scale, skew, rotation, etc of the real world plane you are imaging. Also see https:/

Camera calibrations are often done with a chess board pattern, as it shows scale, skew, rotation, etc of the real world plane you are imaging. Also see https://en.m.wikipedia.org/wiki/Chessboard_detection https://en.m.wikipedia.org/wiki/Chessboard_detection.