Tsai’s camera calibration method revisited

A calibration target can be imaged to provide correspondences between points in the image and points in space. It is, however, generally impractical to position the calibration target accurately with respect to the camera coordinate system using only mechanical means. As a result, the relationship between the target coordinate systemand the camera coordinate system typically also needs to be recovered from the correspondences. This is referred to as exterior orientation in photogrammetry.