Automatic extraction and building change detection from digital surface model and multispectral orthophoto

Abstract

The update of topographic databases is an important task fir organizations that maintain them. Building data are one of the important data types in topographic databases. The article describes a method for automatic building extraction from digital surface model and multispectral orthophoto and the use of extraction results for the building change detection in the topographic database. The initial building mask was created from the normalized digital surface model (nDSM). Vegetation was eliminated from the building mask using a modified vegetation index calculated from the infrared orthophoto and also considering the shadow index and the nDMP texture. The final building mask was vectorised using Radon transform, The results of the automatic building extraction were compared to the building cadastre and the actual situation on the ground. The automatic method detected 94.4% of all buildings in the area. We concluded that the described method is appropriate for capturing of the building data for the topographic database in scales 1: 10 000 and smaller. Automatic change detection results (completeness 93.5% and correctness 78.4%) indicate that the described method is appropriate for building change detection.