https://play.google.com/store/apps/details?id=com.FabulousPixel.TuscanyDive&hl=en I had recorded a side-by-side video with the 'tuscany dive' app from the above link.
I think the mapping is similar to the stereo mapping, but now I'm stuck on the step of camera calibration. Since there is no real camera here, I can't do this just like the one introduced in tutorial.
Is there any easy way to do the calibration here? Is there any other way to do the mapping?
You can guess the camera parameters. If the images have no distortions (they are rectified), you can use the "Simple calibration" button to generate calibration file for you.
In the example below, we are creating a calibration file named "video". By clicking "Simple calibration", set these parameters:
fx = 525
fy = 525
cx = 0
cy = 0
baseline = 0.11
These parameters are from the Bumblebee2 camera calibration. You may need to tune the focal and baseline depending on the simulated stereo camera. For virtual reality, the baseline may be between 50–75 mm (so 0.05-0.075 m).
This will save the calibration files to working directory. When starting mapping, RTAB-Map looks in the "camera_info" folder for files named with "video" prefix.