How to verify that the camera calibration is correct? (or how to estimate the error of reprojection)

Question

The quality of calibration is measured by the reprojection error (is there an alternative?), which requires a knowledge world coordinates of some 3d point(s).

Is the

Answer 1

On Engine's question: the pose matrix is a [R|t] matrix where R is a pure 3D rotation and t a translation vector. If you have computed a homography from the image, section 3.1 of Zhang's Microsoft Technical Report (http://research.microsoft.com/en-us/um/people/zhang/Papers/TR98-71.pdf) gives a closed form method to obtain both R and t using the known homography and the intrinsic camera matrix K. ( I can't comment, so I added as a new answer)