Fig. 1. Block diagram of automatic dimming method of EO system

Fig. 2. Flow chart of automatic detection and dimming

Fig. 3. Several divisions of metering window

Fig. 4. Histogram and convolution sum

Fig. 5. Extraction of non-areas of interest

Fig. 6. Results of reconnaissance image analysis

Fig. 7. Information entropy corresponding to img_6

Fig. 8. Schematic diagram of automatic gain/shutter control

Fig. 9. Metering area settings

Fig. 10. Improved electronic shutter and gain control methods

Fig. 11. Two scene images with the same average gray value

Fig. 12. Diagram of statistical method of sliding window

Fig. 13. Adjustment flow chart under scanning conditions

Fig. 14. Flow chart of contrast correction algorithm

Fig. 15. Relationship between gain factor and pixel brightness of simulation data

Fig. 16. Verification results of automatic dimming before scanning imaging