  Structure from motion using uncalibrated multi-camera systems is a
challenging task. This paper proposes a bundle adjustment solution that
implements a baseline constraint respecting that these cameras are static to
each other. We assume these cameras are mounted on a mobile platform,
uncalibrated, and coarsely synchronized. To this end, we propose the baseline
constraint that is formulated for the scenario in which the cameras have
overlapping views. The constraint is incorporated in the bundle adjustment
solution to keep the relative motion of different cameras static. Experiments
were conducted using video frames of two collocated GoPro cameras mounted on a
vehicle with no system calibration. These two cameras were placed capturing
overlapping contents. We performed our bundle adjustment using the proposed
constraint and then produced 3D dense point clouds. Evaluations were performed
by comparing these dense point clouds against LiDAR reference data. We showed
that, as compared to traditional bundle adjustment, our proposed method
achieved an improvement of 29.38%.
