Stereo calibration using two cameras and 3D reconstruction of an Object?

I have two cameras setup as shown in following picture:

What I have with this setup:

• Top view of this green object with (x1,y1) as its 2D image coordinates.
• Side view of this green object with (x2,y2) as its 2D image coordinates.

How can I trace/identify real world 3D coordinates (x,y,z) of this green object via these two cameras (i.e combination of top view image and side view image)?

I know how to calibrate single camera using JavaCV/OpenCV but I don't know how perform stereo calibration other stuff using JavaCV/OpenCV.

What is the step-by-step procedure for doing such stereo calibration via two cameras?

What would be the output (e.g., intrinsic matrix, distortion etc.) of such a stereo calibration process and how can I use that output in order to compute the real world 3D coordinates of this green object?

After looking at the picture,I think you may face problem in implementing stereo algorithms for your a setup. The stereo rectification works well when the cameras are almost fronto-parallel . For your camera setup, you can hardly get any rectified image on which you could find any disparity matching.