Fig. 1. Schematic of machine vision imaging system

Fig. 2. Sequence images of the inner wall of a cylindrical workpiece focused at different positions. (a) Top; (b) upper middle; (c) lower middle; (d) bottom

Fig. 3. Multi-focus image fusion network structure

Fig. 4. CNN multi-focus image fusion process

Fig. 5. Schematic of panorama expansion method

Fig. 6. Ring-shaped shots of the inner wall of a cylindrical workpiece at different positions. (a) Top; (b) upper middle; (c) lower middle; (d) bottom

Fig. 7. Comparison of inner wall of cylindrical workpiece 1 with different methods. (a) CNN; (b) DSIFT; (c) DWTDE

Fig. 8. Comparison of inner wall of cylindrical workpiece 2 with different methods. (a) CNN; (b) DSIFT; (c) DWTDE

Fig. 9. Comparison of annular expansion of cylindrical workpiece 1. (a) Panoramic ring image expansion; (b) improved method expansion

Fig. 10. Comparison of annular expansion of cylindrical workpiece 2. (a) Panoramic ring image expansion; (b) improved method expansion