Fig. 1. Overall flowchart

Fig. 2. Calibration plates. (a) Positive view of the calibration plate; (b) Side view of the calibration plate; (c) Thermal imge of the calibration plate; (d) Binarization and inversion of the thermal image

Fig. 3. Angle iron and thermal images

Fig. 4. Contour extraction directly from thermal images

Fig. 5. Remapped heat map and profile extraction results

Fig. 6. Extracted contours of different targets, backgrounds, and distances

Fig. 7. Imaging principle

Fig. 8. Geometric constraints

Fig. 9. Geometric constraints in imaging

Fig. 10. Thermal imager and object coordinate system

Fig. 11. 3D model projected onto a heat map

Fig. 12. Projection process

Fig. 13. Thermal imager and angle iron

Fig. 14. 3D model of the angle iron

Fig. 15. Acquired thermal images

Fig. 16. Surface temperature field reconstruction results

Fig. 17. Reconstruction results (the left image of each image shows the acquired thermal image, and the right image shows the corresponding reconstruction results). (a) Replacement of background diagonal iron reconstruction at 1.2 m; (b) Reconstruction of the angular iron with the addition of interference at 1.2 m; (c) Reconstruction of a rectangular iron box placed in opposition at 0.6 m; (d) Reconstruction of an aluminium box of a horizontal cuboid at 0.5 m

Fig. 18. ArUco labeling and visible light camera + thermal imager solution (comparative validation tests)

Fig. 19. Visible and thermal maps with ArUco marking

Fig. 20. Reconstruction results of the poseobtained by ArUco

Fig. 21. Z-axis translational radar plot