The objective of the EuroSDR Building Extraction project was to evaluate the quality, accuracy, feasibility and economical aspects of semi-automatic and automatic building extraction based on laser scanner data and/or aerial images. Data sets from four test sites were delivered to the eleven participants of the project. For each test site the following data were available and could be downloaded from the FGI ftp-site: aerial images, camera calibration and image orientation information, ground control point coordinates and jpg-images of point locations (with the exception of Amiens), laser scanner data and cadastral map vectors of selected buildings (vector ground plans). In this report the used test sites, data sets as well as used reference data are described. The building extraction methods used by the participants and methods used in accuracy evaluation are explained. Produced 3D city models are depicted and analysed especially in respect to accuracy, used data and the level of automation. Finally, discussion and conclusions are given summarizing the results of the project.

Presently, photogrammetric techniques and hybrid techniques provide the highest accuracy and level of detail in 3D city reconstruction. Despite the high amount of research during the last decade the level of automation is still relatively low. Improvement in automation can be achieved most significantly by utilising the synergy of laser and photogrammetry. The photogrammetric techniques are powerful for visual interpretation of the area, measurement of the building outlines and of small details (e.g. chimneys), whereas laser scanning gives height, roof planes and ridge information at its best. Presently, photogrammetric techniques and hybrid techniques provide the highest accuracy and level of detail in 3D city reconstruction. Despite the high amount of research during the last decade the level of automation is still relatively low. Improvement in automation can be achieved most significantly by utilising the synergy of laser and photogrammetry. The photogrammetric techniques are powerful for visual interpretation of the area, measurement of the building outlines and of small details (e.g. chimneys), whereas laser scanning gives height, roof planes and ridge information at its best.