Abstract
Shadows in remote sensing images often result in problems for various applications such as land-cover classification, change detection, and damage detection in disasters. Due to these reasons, it is very useful if the radiance of shadowed areas is corrected to the same radiance as shadow-free areas. In this study, a shadow detection and correction method was proposed. Shadowed areas were detected by object-based classification, using brightness values and a neighbor relationship. Then the detected shadowed areas were corrected by a liner function to produce a shadow-free image. The shadowed areas with different darkness were corrected with different ratios to improve the accuracy of the result. The spectral characteristics of sunlit and shadowed areas in a QuickBird image were studied and then the shadow-free radiance was obtained.
