Automatic object extraction from aerial imagery - A survey focusing on buildings

This paper surveys the state-of-the-art automatic object extraction techniques from aerial imagery. It focuses on building extraction approaches, which present the majority of the work in this area. After proposing well-defined criteria for their assessment, characteristic approaches are selected and assessed, based on their models and strategies. The assessment gives rise to a combined model and strategy covering the current knowledge in the field. The model comprises: the derivation of characteristic properties from the function of objects; three-dimensional geometry and material properties; scales and levels of abstraction/aggregation; local and global context. The strategy consists of grouping, focusing on different scales, context-based control and generation of evidence from structures of parts, and fusion of data and algorithms. Many ideas which have not been explored in depth lead to promising directions for further research. (C) 1999 Academic Press.