Fig. 1. Diagram of proportional coefficient method

Fig. 2. Diagram of local linear fitting method

Fig. 3. Exposure time variation after applying damping

Fig. 4. Flow chart of status I

Fig. 5. Overall flowchart of status II-V

Fig. 6. Flow chart of algorithm 1

Fig. 7. Flow chart of status II

Fig. 8. Possible combinations of exposure in state II

Fig. 9. Flow chart of algorithm 2

Fig. 10. Flow chart of status III

Fig. 11. Flow chart of status IV

Fig. 12. Flow chart of status V

Fig. 13. Experimental images of the automatic exposure algorithm. (a) Experimental images of biological slices under a microscope; (b) OLED screen under a stereomicroscope; (c) (d) exposure results when the ROI is placed in different positions

Fig. 14. Grayscale histogram of Fig. 13 (c)，(d)

Fig. 15. The curves of exposure time variation over time. (a) Introducing adaptive damping; (b) not introducing adaptive damping