Fig. 1. Flowchart of shaded roads extraction with brightness compensation method

Fig. 2. Image preprocessing of linear stretch and bilateral filter

Fig. 3. Shadow extraction on HSI space with threshold segmentation

Fig. 4. Brightness compensation over shadow areas

Fig. 5. Brightness compensation over shadow areas for the shaded road extraction

Fig. 6. Comparison of the K-means and K-means++ algorithms in extracting unshaded roads with threshold segmentation

Fig. 7. Definition of shape endpoints in outline reparation method

Fig. 8. Data source for the verification experiment

Fig. 9. Results of unshaded roads extraction with threshold segmentation in HSI space and K-means algorithm

Fig. 10. Shaded roads extraction and preprocessing

Fig. 11. Result of shaded roads extraction based on the brightness compensation method

Fig. 12. Comparison of brightness compensation method and traditional shadow coefficient amendment method in rough extraction of shaded roads