Roof-top detection based on structural elements combination

A novel roof-top extraction method for satellite images based on probabilistic topic model is presented. We model roof-top as the connected structural elements. The proposed method contains two major steps: 1) Detect structural elements, different from earlier structure detector, the proposed method automatically learn the types of elements from unlabeled samples; 2) Connect these elements to form roof-top boundary, where the relationships between elements are estimated by hierarchical topic model. This approach belongs to generative method where only a small number of roof-top samples are required. The experimental results demonstrate the effectiveness of the proposed approach.