Fast and efficient extraction of building models from airborne lidar data is an important research topic in applications of airborne lidar system.The semi-automatic method with user's interaction is a practicable approach for extracting simple and regular buildings from point cloud data.Based on this view

a method of interactively extracting gable-roofed building models from lidar point cloud data is proposed in this paper.An improved Hough transformation in 3D space and Cluster Analysis Model are key points of this approach.The proposed method consists of three steps.First

the user roughly input a region where a building is located.The candidate points belonging to the building roof are then filtered out.Second

an improved Hough transformation in 3D space and Cluster Analysis Model are applied to the data set of roof points to acquire parametric expressions of roof planes.The third step is to construct the integrated building model.The roof's ridge line is obtained by intersecting roof planes

and the building's footprint is determined by analysis of roof points.Finally

a complete building model is created by adding vertical walls.Tested with sample lidar data from Optech Company

this approach gets good experimental results with very few user interactions needed.