Fig. 1. Original image and reproduction results of two scenes. (a) Original image of complex scene; (b) original image of simple scene; (c) processing result of complex scene; (d) processing result of simple scene

Fig. 2. Flow chart of recognition algorithm of aerial pavement crack

Fig. 3. Schematic of region growing based on multi-directional fitting. (a) Pixel labeling; (b) growing pixel; (c) growing region; (d) multi-directional fitting region

Fig. 4. Results of road extraction. (a) Traditional region growing; (b) region growing based on multi-directional fitting

Fig. 5. Comparison of detection results. (a) Traditional edge detection; (b) edge detection based on significance analysis

Fig. 6. Display results of crack length. (a) Detection result of left road; (b) detection result of right road