Fig. 1. Gray-scale statistics of laser stripe cross-section

Fig. 2. Images of casting slab

Fig. 3. Gray scale surfaces of casting slab

Fig. 4. Image processed by background difference method

Fig. 5. Gray value curves at line 2560th row

Fig. 6. Optimization principle of gray-gravity method

Fig. 7. Scene of three-dimensional measurement system for casting slab

Fig. 8. Image of ROI extraction fragment of line-structured light

Fig. 9. Adaptive gray threshold

Fig. 10. Comparison of extraction errors of different stripe center extraction methods

Fig. 11. Extraction results of different laser lines with different brightnesses

Fig. 12. Line-structured light on surface of casting slab and its three-dimensional reconstruction