Fig. 1. Projection method

Fig. 2. Candle flames

Fig. 3. Projected light intensity and Gaussian fitting curve

Fig. 4. Flow chart of algorithm

Fig. 5. Coordinates positioning

Fig. 6. Schematic diagram of experimental setup

Fig. 7. Moire fringes of candle-air flame flow field

Fig. 8. Moire fringes of air flow field with heated soldering iron

Fig. 9. Moire fringes of propane-air flame flow field

Fig. 10. Moire fringes with different contrasts

Fig. 11. Moire fringes with different widths

Fig. 12. Extraction results of effective areas

Fig. 13. Extraction results of effective areas

Fig. 14. Extraction results of effective areas