Extraction of building footprints from airborne laser scanning: Comparison and validation techniques

Many applications in urban planning and analysis require the position and extent of buildings, the so-called building footprint. Cadastral maps acquired by ground based surveying are often not up-to-date or may not be available at all. Airborne laser scanning, on the other hand, offers the possibility to detect the roof outlines in an automated manner. This subject has been researched in the previous years, but a final comparison of the quality of these algorithms has not been performed. Additionally, the methods for assessing the quality of building footprint extraction should consider the special characteristics of airborne laser scanning data. This paper gives an overview of the algorithms developed for the task of house detection from airborne laser scanning and evaluates two algorithms experimentally. The methods of quality assessment are discussed and next to the standard method of pixel based comparison the object based comparison is studied, providing more insight.