Visual odometry from the images of the reference surface with small interframe rotations

The paper considers the problem of visual odometry based on a sequence of video frames formed using a camera perpendicularly downward facing the reference surface. The problem is solved under the assumption that the shooting frequency is high, so that the interframe rotation and shift parameters are small. The technology is implemented in the form of a sequence of the following steps: determining the shift and rotation with an accuracy of an integer number of pixels using the correlation method, clarifying the shift and rotation parameters using the optical flow method, and correcting estimation errors associated with uneven motion and fluctuations in the distance of the camera to the reference surface by estimating deviations of local calibration characteristics from their mean values. The results of experimental studies of the technology on test trajectories obtained by simulating the motion of a vehicle along the reference surface are presented.