Fig. 1. Filtering and unwrapping results of computer-simulated noise phase pattern. (a) Computer-simulated phase pattern; (b) filtering result of mean value; (c) filtering result of RBF; (d) unwrapping result of noiseless phase pattern; (e) unwrapping result of Fig.(b) with quality map method; (f) unwrapping result of Fig.(c) with quality map method; (g) unwrapping result of Fig.(b) with DCT method; (h) unwrapping result of Fig.(c) with DCT method

Fig. 2. Specimen of three-point bending

Fig. 3. Nuclear graphite ESPI phase patterns at different moments. (a) 1st moment; (b) 3rd moment; (c) 7th moment; (d) 10th moment; (e) 13th moment; (f) 16th moment

Fig. 4. [in Chinese]

Fig. 5. (a)-(f) Unwrapping phase images of Fig.4 (a)-(f), respectively

Fig. 6. (a)-(f) Contour lines of unwrapping phase of Fig. 5(a)-(f), respectively

Fig. 7. Schematic of crack evolution of specimen