Fig. 1. Panoramic annular imaging

Fig. 2. Camera model. (a) PAL camera model; (b) image plane; (c) sensor plane

Fig. 3. Flowchart of PASVO algorithm

Fig. 4. Panoramic annular semantic segmentation (PASS)

Fig. 5. Correspondence search along epipolar curve under semantic guidance. (a) One of the keypoints; (b) searching matching points along polar curve under semantic guidance

Fig. 6. Keypoints extraction under semantic guidance. (a) Semantic segmentation result; (b) confidence distribution; (c) original keypoints extraction; (d) keypoints extraction under semantic guidance

Fig. 7. Experiment setup. (a) Remote control vehicle; (b) PAL image expands to a perspective image

Fig. 8. Effectiveness test of keypoints extraction under semantic guidance. (a) Proportion of inliers with/without semantic guidance; (b) RANSAC convergence probability with/without semantic guidance

Fig. 9. Error between trajectory estimated by PASVO and reference trajectory in the accuracy test. (a) S1; (b) S5; (c) S6

Fig. 10. Trajectories estimated by the different algorithms on the large-scale dataset. The black dot represents the starting point, and dots with different colors denote the end points of the trajectory estimated by different algorithms