Fig. 1. Schematic diagram of dark field detection principle

Fig. 2. A conventional light source illuminates the surface of the ball

Fig. 3. Incident light simulation

Fig. 4. Single scan path diagram

Fig. 5. Ball pretreatment process

Fig. 6. Cylindrical projection diagram

Fig. 7. Part of the image before and after low frequency filtering

Fig. 8. Spherical three-dimensional coordinate system

Fig. 9. Algorithm verification using two-dimensional graph

Fig. 10. Single sphere-ring reconstruction experiment

Fig. 11. Point rotation diagram

Fig. 12. Spherical three-dimensional point cloud stitching process

Fig. 13. Triangulation diagram

Fig. 14. Traditional bright field array detection

Fig. 15. Defect area dark field linear array detection results

Fig. 16. Two steel balls under test

Fig. 17. Non-destructive steel ball dark field line scanning image

Fig. 18. Dark field line scanning image of worn steel ball

Fig. 19. 3D reconstruction results of surface defects of steel ball

Fig. 20. Filter results of defect points in 3D point cloud model