How Kitti calibration matrix was calculated?

Question

I working with other dataset (no kitti), but I need to convert it in kitti dataset format. I can\'t understand how calibration matrices were calculated in kitti. Example:

<

Answer 1

According to the file calib_cam_to_cam.txt(calib_time: 09-Jan-2012 14:00:15) provided on Kitti Website - http://www.cvlibs.net/datasets/kitti/eval_object.php?obj_benchmark=3d, the above mentioned matrix is for Camera 01(P_rect_01). As mentioned in the paper Vision meets Robotics: The KITTI Dataset by Andreas Geiger, Philip Lenz, Christoph Stiller and Raquel Urtasun(Section IV B - camera calibration), projection matrix for i-th camera -

P(i)rect = [[fu 0  cx  -fu*bx],
            [0  fv  cy  0],
            [0   0   1  0]]

where, bx is the baseline in meters w.r.t. the reference camera 0. The sensor setup as shown on Kitti website - http://www.cvlibs.net/datasets/kitti/setup.php indicates baseline between cam 3 and cam 2 is 0.54m and baseline between cam 0 and cam 2, and cam 1 and cam 3 is 0.06m.

Now, -fu*bx/fu = -386.1448/718.856 ~= -0.537165 ~= -0.54 (B3-2 - B2-0 + B1-3 = B1-0)