Opencv 3D from points in stereo pair

Question

Is there a simple function in OpenCV to get the 3D position and pose of an object from a stereo camera pair?

I have the cameras and baseline calibrated with the chess bo

Answer 1

After calibrating your stereo camera system, you have got the relative pose (=translation+orientation) between the two cameras. Using solvePnP/solvePnPRansac if you find the relative pose between one of the cameras and the object and then consequently you have got the relative pose between the object and the other camera as well. For example, in stereo systems used for robot navigation usually reconstructed 3D points from previous frames are matched against only one of the cameras and then the relative camera pose from the 3d points is estimated. The stereo system just eases and improves the quality of triangulation/structure reconstruction.