The Finnish Geodetic Institute coordinates the EuroSDR/ISPRS Tree Extraction project, which started at the end of 2004. The objective of this project was to evaluate the quality, accuracy, and feasibility of automatic or semi-automatic tree extraction methods based on high-density laser scanner data and digital image data. The sub-objectives include

• How much variation is caused by the methods in the tree extraction.
• How much the point density of laser data affects tree extraction.
• How much the results can be improved by integrating laser scanner data and aerial image data.