Fig. 1. Diagram of image acquisition system

Fig. 2. Obtained images under three lighting schemes. (a) Coaxial light source; (b) backlight source; (c) coaxial light source and backlight

Fig. 3. (a) Extraction bearing inner and outer rings; (b) a new circle produced under the traditional CHT model; (c) the estimated circle center

Fig. 4. Segmentation of bearing inner and outer rings

Fig. 5. Schematic of bearing expansion. (a) Ring expansion; (b) pixel correspondence before and after ring expansion

Fig. 6. Polar coordinate expansion of a perfect bearing (a) and a roller missing bearing (b)

Fig. 7. Data extraction of a perfect bearing (a) and a roller missing bearing (b)

Fig. 8. Identification results of a perfect bearing (a) and a roller missing bearing (b)