Building Contours Extraction from Light Detect and Ranging Data

In order to construct the city three dimensional (3D) building model, building contours must be extracted in fast and accurately. Traditional engineering survey and photogrammetry method is low efficient to do this. The Light Detect and Ranging (LiDAR), so called Airborne Laser Scanning, works on the same principle as radar except using light waves instead of radio waves. It can measure distance and get high density raw laser point data (so called point cloud) by the way of scanning ground objects. We can produce city Digital Surface Model (DSM) in a fast rapid via LiDAR point cloud and modern computer. And the DSM is an important basis to build 3D digital city. Due to the LiDAR point cloud data are noncontinuity in distribution, interval and in density, it is difficult to extracted buildings contours from the single point cloud data. In this paper, we extract urban building contours to use digital image processing technology from the airborne LiDAR points cloud data without any assistance data. This way can rapidly extract building contours with low cost in a large urban area. The result shows it is universally applicable for extract urban building contours from raw LiDAR point cloud.