Modelling the Extraction of Field Boundaries and Wind Erosion Obstacles from Aerial Imagery

In this paper work on image analysis methods extracting field boundaries and wind erosion obstacles from aerial imagery is presented. Describing the objects of interest and additional GIS-data together in an integrated semantic model is essential to get an overview of the numerous relations between the different objects and how to exploit the prior knowledge. The strategy is derived from the modelled characteristics taking into account an automatic processing flow. The field boundaries and wind erosion obstacles are first extracted separately: A segmentation within selected regions of interest in the imagery leads to field areas, which are split, if necessary, to preliminary fields. Furthermore, a snake algorithm is initialized to correct the geometric inaccuracies in some parts yielding final field boundaries. Wind erosion obstacles are derived using DSM-data in addition to the imagery to verify search areas from the prior GIS knowledge, for example parallel and nearby roads, or to extract wind erosion obstacles without prior information about their location. Finally, a combined evaluation of the different objects is accomplished to exploit the modelled geometrical similarities resulting in a refined and integrated solution. Results of the different steps prove the potential of the proposed solution.