Table 6: Number of matched feature points needed.

methodTerrainANMFP

1 ours () Plain 57.1
2 ours () Plain 58.5
3 ours () Plain 56.1
4 ours () Plain 55.2
5 ours () Plain 63.3
6 ORB-SLAM2 Plain 297.3
7 DSO Plain 1907.1
8 ours () Mountainous 78.7
9 ours () Mountainous 68.2
10 ours () Mountainous 74.9
11 ours () Mountainous 66.2
12 ours () Mountainous 71.1
13 ORB-SLAM2 Mountainous 254.8
14 DSO Mountainous 1953.8