upon further investigation, it appears that one argument gets assigned to the dst parameter, and the intended parameter is never given a value.
The function signature is:
undistortPoints(src, cameraMatrix, distCoeffs[, dst[, R[, P]]]) -> dst
fix this by using named arguments:
further, I would recommend care with the shape of the src argument. OpenCV does have some tolerance for weirdly shaped data but generally it expects a column vector of 2-channel elements. if you had just two points, the corresponding 2x2 array would be ambiguous. it’s best to establish a shape of (N, 1, 2) which is unambiguous.