SEMI-AUTOMATIC ROAD EXTRACTION FROM DIGITAL AERIAL PHOTOGRAPHS

摘要

By means of the progress in photogrammetry; it is now possible to produce the maps of huge areas more quickly and economically but the production steps are still expensive and time consuming. In recent years, parallel to the development in photogrammetry, more effective methods are researched to make available digitizing line features like roads full automatically or semi-automatically from digital aerial photographs. Because it is not still possible to designate the full automatic feature extraction methods clearly, the semi-automatic feature extraction methods, which combine experienced interpretation of an operator with the speed of an computer algorithm, are the best solutions. There are different semi-automatic approaches for digitizing features from digital aerial photographs. Nowadays, suitable methods for each specific mission are chosen in the literature, instead of one exact method which carries out all alternative algorithms. In this paper, roads are chosen as line features for digitizing from digital aerial photographs, because roads are the most time consuming features to digitize in photogrammetry. Two road extraction algorithms are applied to digitize roads from mono digital aerial photographs and the results are compared.