Fig. 1. Flow chart of our algorithm

Fig. 2. Schematic diagram of line segment grouping strategy

Fig. 3. Schematic diagram of the common junction

Fig. 4. Schematic diagram of the line segment screening strategy. (a) Line segment extracted by the improved LSD algorithm; (b) line segment to be matched

Fig. 5. Affine invariance characteristics of point and line fusion features

Fig. 6. Line segment detection results of different algorithms. (a) Original image; (b) LSD algorithm; (c) our algorithm

Fig. 7. Trajectory errors of different algorithms. (a) Sequence 01; (b) sequence 07; (c) sequence 03; (d) sequence 10

Fig. 8. Maps constructed by different algorithms. (a) Image sequence V1-03-difficult; (b) image sequence MH_04_difficult

Fig. 9. Image of a real corridor

Fig. 10. Camera pose errors of different algorithms. (a) X direction; (b) Z direction