STEREO NOT TESTED YET!
Modified from camera_calibration
This modified version can save calibrationdata.tar.gz at any time, regardless of calibrated or not. You don't need to wait for the long calibration time when you just need the raw images.
Also, it will pop up a window showing where the saved chessboards are.
For example:
There is also another simple and naive tool: publish_calib_file.py, for publishing all png files in the current folder.
There is also a python script kalibr_camera_focus from https://github.com/ethz-asl/kalibr/blob/master/aslam_offline_calibration/kalibr/python/kalibr_camera_focus to help adjusting focus of the camera.