Fig. 1. Video acquisition system

Fig. 2. Images of quadruped walking

Fig. 3. Flow chart of automatic identification of motion feature

Fig. 4. Structure of DeeplabV3+

Fig. 5. Multiscale feature fusion module

Fig. 6. DUpsampling

Fig. 7. Improved DeeplabV3+

Fig. 8. Comparison of effects of semantic segmentation.(a) Original image; (b) PSPNet; (c) Segnet; (d) Unet; (e) DeeplabV3+; (f) improved DeeplabV3+Xception

Fig. 9. Flow chart of motion corner detection and matching

Fig. 10. Schematic diagram of corner swing angle

Fig. 11. Local maximum values

Fig. 12. Corner detection of quadrupeds. (a) Corners of rhino without overlap; (b) forelimb corners of rhino with overlap; (c) hindlimb corners of buffalo with overlap; (d) forelimb corners of alpaca with overlap

Fig. 13. Curves of corner distance variation

Fig. 14. Gait cycle of each limb

Fig. 15. Motion corner detection and matching

Fig. 16. Rhino’s corner distance variation curves

Fig. 17. Rhino’s gait cycle of each limb

Fig. 18. Buffalo’s corner distance variation curves

Fig. 19. Buffalo’s gait cycle of each limb

Fig. 20. Alpaca’s corner distance variation curves

Fig. 21. Alpaca’s gait cycle of each limb

Fig. 22. Gait sequences. (a) Gait sequence of buffalo; (b) gait sequence of rhino; (c) gait sequence of alpaca

Fig. 23. Corner swing angles. (a) Corner swing angle of rhino; (b) corner swing angle of buffalo; (c) corner swing angle of alpaca

Fig. 24. Corner detection for different scales. (a) R=1.06%; (b) R=3.25%; (c) R=6.24%