Fig. 1. Wire rope detection system

Fig. 2. Damaged wire rope sample

Fig. 3. Hyperspectral images of wire rope with defects. (a) 410 nm band image; (b) 470 nm band image; (c) 566 nm band image; (d) 661 nm band image; (e) 737 nm band image; (f) 793 nm band image

Fig. 4. Spectral curves of the wire rope area with the defect and the background area. (a) Reflectivity of randomly selected ROIs; (b) two parts of ROI reflectivity after average processing

Fig. 5. Hyperspectral images and gray histograms. (a) 406 nm band image and its grayscale histogram; (b) 566 nm band image and its grayscale histogram; (c) 645 nm band image and its grayscale histogram

Fig. 6. Image threshold segmentation results at different wavelengths. (a) 406 nm band image; (b) 566 nm band image; (c) 645 nm band image

Fig. 7. Comparison of edge detection results based on different operators. (a) Roberts operator; (b) Sobel operator; (c) Prewitt operator; (d) Canny operator

Fig. 8. Hyperspectral images after Hough transform. (a) Based on Roberts operator; (b) based on Sobel operator; (c) based on Prewitt operator; (d) based on Canny operator