  Recovering the absolute metric scale from a monocular camera is a challenging
but highly desirable problem for monocular camera-based systems. By using
different kinds of cues, various approaches have been proposed for scale
estimation, such as camera height, object size etc. In this paper, firstly, we
summarize different kinds of scale estimation approaches. Then, we propose a
robust divide and conquer the absolute scale estimation method based on the
ground plane and camera height by analyzing the advantages and disadvantages of
different approaches. By using the estimated scale, an effective scale
correction strategy has been proposed to reduce the scale drift during the
Monocular Visual Odometry (VO) estimation process. Finally, the effectiveness
and robustness of the proposed method have been verified on both public and
self-collected image sequences.
