Shadow detection in remote sensing images based on weighted edge gradient ratio

This paper presents a novel shadow detection method in remote sensing images based on edge feature description of candidate regions. Edge gradient ratio is defined and used to represent the inherent properties of shadow regions. To improve the detection result, weighted edge gradient ratio (WEGR) is addressed, where the weight of a region is determined by the number of pixels belonging to shadow in the region, and edge gradient ratio is proposed to describe the edge feature surrounding the region. Experiments and comparisons indicate that our method achieves better accuracy both on high and low quality remote sensing images.