Fig. 1. Visible plasma image and real-time inversion result of EFIT magnetic surface for EAST divertor configuration

Fig. 2. Image edge for three models. (a) Step edge model; (b) ramp edge model; (c) roof edge model

Fig. 3. Variation trend of plasma image edge pixel. (a) Typical optical boundary region of plasma; (b) pixel change in the typical optical boundary region

Fig. 4. Plasma image edge region after gray processing

Fig. 5. Representation of 4D light field

Fig. 6. MLA-based light field imaging system

Fig. 7. Principle of refocusing imaging

Fig. 8. Schematic of optical sectioning system

Fig. 9. Setup of calibration system

Fig. 10. Refocused images of scale for different α. (a) α=8.3; (b) α=17.4; (c) α=27.0; (d) partial enlargement of scale image

Fig. 11. Relationship between α and refocusing depth D

Fig. 12. Process of PSF calibration. (a) Extraction of edge image; (b) gray level curve; (c) LSF and Gaussian fitting curve

Fig. 13. Defocused blurred images and simulation results. (a) Original image 1; (b) defocused image 1; (c) original image 2; (d) defocused image 2

Fig. 14. Images focusing on different locations. (a) Focus on image 1; (b) focus on image 2

Fig. 15. Iterative deconvolution algorithm for solving systems of equations

Fig. 16. Reconstructed images. (a) Reconstructed image 1; (b) reconstructed image 2

Fig. 17. Verification of the effect of the number of sections. (a) Spatial distribution of section images; (b) superimposed images at each depth; (c) reconstruction results with different number of section images

Fig. 18. Verification of the effect of section intervals. (a) Spatial distribution of sections; (b) superimposed images at each depth; (c) reconstruction results with different section intervals

Fig. 19. Flame experiment system

Fig. 20. Refocused flame images

Fig. 21. Reconstruction results based on original images. (a) Reconstructed images; (b) contours

Fig. 22. Reconstruction effect after flat fielding. (a) Reconstructed images; (b) contours

Fig. 23. 3D view of section stack. (a) Orthogonal view of section stack; (b) view after rotating 15°; (c) view after rotating 90°