Road Network Extraction Using Edge Detection and Spatial Voting

Road network detection from very high resolution satellite images is important for two main reasons. First, the detection result can be used in automated map making. Second, the detected network can be used in trajectory planning for unmanned aerial vehicles. Although an expert can label road pixels in a given satellite image, this operation is prone to errors. Therefore, an automated system is needed to detect the road network in a given satellite image in a robust manner. In this study, we propose a novel approach to detect the road network from a given panchromatic Ikonos satellite image. Our method has five main steps. First, we apply a nonlinear bilateral filtering to smooth the given image. Then, we extract Canny edges and the gradient information as local features. Using these local features, we generate a spatial voting matrix. This voting matrix indicates the possible locations of the road network pixels. By processing this voting matrix in an iterative manner, we detect initial road pixels. Finally, we apply a tracking algorithm on the voting matrix to detect the missing road pixels. We tested our method on various satellite images and provided the extracted road networks in the experiments section.