Detection of roads from satellite image using optimal search

The automatic detection of roads from satellite images is a very important problem. In this paper a new method is proposed which can overcome drawbacks of current road detection theories and can detect multiple roads in an image. Firstly binary images representing edges are used to evaluate the possibility for a road to pass on a given pixel. An 8-directions filter, a clearing filter and a parallel-edge-detection filter are proposed which can bring insufficient local information to each other to obtain enough global information to detect a road and by which the possibility of a road-passing on the pixel can be effectively evaluated. Secondly, by using the Hough transform and the optimal search method a complete road can be detected. This detection theory does not depend on the size of an image and can detect multiple roads in an image including intersecting roads and T-type roads