Fig. 1. Schematic of the interference fringe image acquisition system

Fig. 2. Flow chart of interference fringe image processing

Fig. 3. Interference fringe binary image. (a) Original image; (b) grayscale image; (c) binary image

Fig. 4. Preprocessed images. (a) Gaussian filtering denoising image; (b) ossification image; (c) deburring image

Fig. 5. Improved template

Fig. 6. Image processed by Canny operator

Fig. 7. Images after Hough transform processing. (a) Hough transform matric display; (b) Hough transform line detection

Fig. 8. Interference fringe bending amount a1, a2, a3 value maps

Fig. 9. Interference fringe spacing b1, b2, b3 value maps