Yes, I am using the correct checkerboard. I am doing everything correctly. I am knee deep in the calibrator.py source, and everything looks good after the StereoCalibrate() command -- the rotation and translation between the two cameras seems reasonable (rotation close to I, translation on the right scale). It seems to be after the set_alpha() call where the final projection matrices end up with HUGE numbers for focal length (tens of thousands), and the rotation matrices have unexpected off diagonal components. Vijay Pradeep wrote: > Hi Patrick, > > Is the checkerboard 8x6 corners? If so, make sure that you always keep > the target in a 'landscape' orientation. If the checkerboard gets close > to a 'portrait' orientation, the OpenCV detector may mess up the > correspondence between both cameras (thus, making the calibration > routine want to rotate one of the cameras 180 degrees). > > This rotational ambiguity can also be solved by using a checkerboard > with [odd]x[even] corners. > > Vijay > > On Tue, Apr 6, 2010 at 2:01 PM, Patrick Beeson > wrote: > > Sorry, I just checked and I am actually using the trunk, not latest. > The problem is that I'm getting large rotational values, and I'm only > ever seeing a horizontal offset in T (top right value in projection > matrix) as non-zero, even though the cameras are at slightly different > heights. I can send the saved tar.gz file that contains the images used > and the ost.txt created if it helps. > > Patrick Beeson wrote: > > I checked out latest and had to do a small bit of changes to sync the > > timestamps of the two cameras whenever frames have very close > > timestamps. So they aren't EXACTLY synced, but VERY closely > synced. I > > can try to send you a screen shot of the output. Note, I am testing > > this with a quite small checkerboard (your checkerboard, but with > 26mm > > squares). Maybe that's the problem? Maybe I'm sampling a space too > > close to the cameras? > > > > Eric Perko wrote: > >> Patrick, > >> > >> What version of camera_calibration are you using? Boxturtle? > >> > >> - Eric > >> > >> On Tue, Apr 6, 2010 at 4:31 PM, Patrick Beeson > > > >> wrote: > >>> I'm trying to calibrate two identical 1394 cameras that are > sitting next > >>> to each other. The stereo calibration from camera_calibration > converges > >>> to VERY bad R and T matrices, rotating the frames and > >>> the warping the images drastically. I've tried several times, with > >>> no luck. > >>> > >>> _______________________________________________ > >>> ros-users mailing list > >>> ros-users@code.ros.org > >>> https://code.ros.org/mailman/listinfo/ros-users > >>> > >> _______________________________________________ > >> ros-users mailing list > >> ros-users@code.ros.org > >> https://code.ros.org/mailman/listinfo/ros-users > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > > > > ------------------------------------------------------------------------ > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users