(a)
(b)
(c)
(d)
(e)
(f)
Figure 10: Initialization results comparison (green: success; red: failed), (a) plain (ours), (b) plain (ORB-SLAM2), (c) plain (DSO), (d) mountainous (ours), (e) mountainous (ORB-SLAM2), and (f) mountainous (DSO).