Re: .db file format and trajectory (odometry) data from .db file
Posted by
matlabbe on
URL: http://official-rtab-map-forum.206.s1.nabble.com/db-file-format-and-trajectory-odometry-data-from-db-file-tp2585p2626.html
Hi,
RTAB-Map should export exactly the same stamps saved in database. Tango doesn't use absolute timestamps, but a
relative one to ensure time correctness:
The Project Tango tablet uses a different timestamp channel other than the system time to ensure the timestamp correctness.
When exporting poses in RGBD-SLAM format, I get for example:
13048.753206 -0.038558 -0.092011 0.025661 -0.090869 0.941459 -0.323810 0.023348
13049.801750 -0.031318 -0.114297 0.072116 -0.094032 0.920353 -0.378536 0.028605
13050.919995 -0.051859 -0.132593 0.169201 -0.103676 0.861276 -0.493519 0.062395
13052.042406 -0.173208 -0.165432 0.250874 -0.107293 0.799779 -0.584281 0.086362
13053.222018 -0.201293 -0.177311 0.255115 0.019472 0.790771 -0.610603 -0.038278
which I is the number of seconds since the device was initialized (not since 1970).
I didn't find any documentation to convert this relative time to absolute time (epoch). There is an interesting comparison of timestamps here:
http://stackoverflow.com/questions/29236110/timing-issues-with-tango-image-framescheers,
Mathieu