How to get the extrinsic parameters for the unrectified case using the camera_calibration package?

I am using the stereo calibration package to calibrate an RGBD camera to achieve higher accuracy. I do not need to rectify the images. Using more accurate intrinsic and extrinsic parameters I could get a more accurate point cloud and uv mapping between pixel coordinates from depth to color image. This is what I need and the ROS calibration package is a good tool to get the images and calculate the camera parameters. The ROS camera calibration package gives the following output for stereo camera calibration: Distortion parameters, intrinsic camera parameters, rectification matrix and projection matrix (**for the processed, rectified image!**). So the intrinsic parameters are readily available. However, what I need in addition is the extrinsic parameters for the non-processed, unrectified image, and I do not know how to get them from this output. I've already searched for my answer in the 'Camera calibration and 3D reconstruction' documentation of OpenCV, but I haven't found my answer. So to summarize, does anyone know how to get the camera poses for the unrectified case?