Abstract:

To balance the contour accuracy and completeness of single threshold Alpha Shapes in extracting point cloud building contours, we present a dual-threshold Alpha Shapes algorithm using a simple ring design concept contour search algorithm to obtain both a good integrity and a relatively high geometric precision of the building’s contour. Furthermore, the initial contour is simplified based on least squares algorithm. In the presence of noise, the simplified contour lines of the present algorithm are closer to the actual contours compared with the classic Douglas Peucker algorithm.

Key words: LiDAR, building boundaries extraction, RANSAC, Alpha Shapes algorithm