Fig. 1. Schematic diagram of defect detection

Fig. 2. Image feature. (a) Physical picture; (b) Speckle pattern interferometry; (c) Projection pattern

Fig. 3. Measuring system

Fig. 4. Physical system

Fig. 5. Projection pattern

Fig. 6. Samples and test results. (a) Sample; (b) Test result

Fig. 7. Out-of-plane displacement gradients

Fig. 8. Projection image. (a) Projection field of view 1; (b) Projection field of view 2; (c) Projection field of view 3; (d) Full-field projection image

Fig. 9. Physical picture. (a) Physical field of view 1; (b) Physical field of view 2; (c) Physical field of view 3; (d) Full-field physical image

Fig. 10. Speckle pattern interferogram. (a) Interferogram 1; (b) Interferogram 2; (c) Interferogram 3; (d) Full-field interferogram

Fig. 11. Split field and full-field images. (a) Sub-field projection image; (b) Sub-field physical image; (c) Sub-field interferogram; (e) Projection image stitching; (f) Physical image stitching; (g) Interferogram stitching