Fig. 1. Schematic diagram of 3D profile measurement based on DFF

Fig. 2. Acquired image sequence

Fig. 3. Curves of the common image sharpness evaluation functions

Fig. 4. Canny operator processing result

Fig. 5. Flow chart of the calculation process of HCVWE function

Fig. 6. Curves of the proposed HCVWE and common image sharpness evaluation functions

Fig. 7. Schematic diagram of the sensitivity factor

Fig. 8. Gaussian fitting result

Fig. 9. Hardware system

Fig. 10. Standard height step

Fig. 11. Scanning and image acquisition process

Fig. 12. Measurement result of the standard step

Fig. 13. Distance from each upper surface point to the lower plane

Fig. 14. Distance from each upper surface point to the upper plane

Fig. 15. Distance from each lower surface point to the lower plane