Use of Topology in Automatic Road Extraction

This paper presents a method for hypothesis verification in automatic road extraction based on the topology of road networks. The method includes the generation of topology of road networks, verification of hypothesized road segments and prediction of missing road segments. The topology of road networks is generated using small scale aerial images as they exhibit a global structure of road networks. The hypotheses of road segments produced in medium scale images are verified using their relationships with the generated topological information of road networks. The missing road segments are also predicted during this process using topological information. An aerial image with an image scale of 1:25,000 in New South Wales is tested. To generate the topology of road network, the images are resampled with a reduction factor of 15. The test results show that the topology of road network can be effectively used to remove spurious hypotheses and to infer the missing road segments.