Fig. 1. Diagram of fluorescent screen scratches, dust and black spots of microchannel plate

Fig. 2. Diagram of circle extraction results by Sobel

Fig. 3. Grey diagram and 3D diagram of LoG operator

Fig. 4. Diagram of detection results for LoG operator

Fig. 5. Diagram of ring segmentation results

Fig. 6. Diagram of halo detection results

Fig. 7. Diagram of non-black spot halo detection results

Fig. 8. Schematic of MCP black spot detection system

Fig. 9. Physical drawing of vacuum cavity

Fig. 10. Diagram of black-spot detection results

Fig. 11. Extraction diagram of black-spot halo under different voltages

Fig. 12. Results diagram of minimum circumscribed circle