Fig. 1. Images of original solder joint and filtering effect

Fig. 2. Images of original core wire end and filtering effect

Fig. 3. HSV color space model

Fig. 4. HSV image of ROI single solder joint

Fig. 5. HSV image of ROI core wire end

Fig. 6. RGB single channel images

Fig. 7. Process of the soldering joint recognition algorithm

Fig. 8. Image of soldering joint segmentation result

Fig. 9. Implementation steps of mask image

Fig. 10. Mask image

Fig. 11. Mask results

Fig. 12. Schematic of contour center point

Fig. 13. Solder joint recognition results

Fig. 14. Flowchart of core wire end recognition algorithm

Fig. 15. Image multiplication

Fig. 16. Contrast enhancement effect

Fig. 17. Histogram equalization

Fig. 18. Morphological filtering

Fig. 19. Comparison of segmentation results

Fig. 20. Flowchart of connected domain analysis algorithm

Fig. 21. Core wire end recognition result

Fig. 22. Calibration results

Fig. 23. Algorithm comparison

Fig. 24. Solder joint recognition results of different cases

Fig. 25. Solder joint recognition results of two methods

Fig. 26. Schematic of solder joint distribution and naming method

Fig. 27. Core wire end recognition results of two methods