Fig. 1. Basic framework of algorithm

Fig. 2. Flow chart of face recognition and age estimation system

Fig. 3. Diagrams of experimental scenes. (a) Diagram of real experimental scene; (b) schematic diagram of experimental scene

Fig. 4. Face detection rate in varying illumination environment

Fig. 5. Face images with different dimming levels at distances of 1, 2 and 3 m, dimming interval is 10%. (a) Face images collected at 1 m, dimming level is 20%-100% from left to right; (b) face images collected at 2 m, dimming level is 30% ~100% from left to right; (c) face images collected at 3 m, dimming level is 40%-100% from left to right

Fig. 6. MAE of age estimation for different models at distances of 1, 2 and 3 m. (a) 1 m; (b) 2 m; (c) 3 m

Fig. 7. Face recognition rate before and after adding image enhancement algorithm in varying illumination environment

Fig. 8. MAE of human face age before and after adding image enhancement algorithm in varying illumination environment

Table 1. Comparison results of gray mean value, recognition rate and MAE before and after adding image enhancement algorithm at distances of 1, 2 and 3 m