Get or Set the DistortionCoeffs ( as a 5x1 (default) or 4x1 matrix ).
The ordering of the distortion coefficients is the following:
(k1, k2, p1, p2[, k3]).
That is, the first 2 radial distortion coefficients are followed by 2 tangential distortion coefficients and then, optionally, by the third radial distortion coefficients. Such ordering is used to keep backward compatibility with previous versions of OpenCV
