A framework for interpretation of aerial images

A general framework for building aerial image interpretation systems is proposed. Within this framework, scene knowledge, which is frequently hierarchical and structured in nature, is represented using frames. Domain problem-solving knowledge, which is typically heuristic in form, is declaratively specified through the use of production rules. The issue of efficient search is addressed by the use of an assumption-based truth maintenance system (ATMS). Within these guidelines, a system has been implemented with the goal of detecting a class of buildings in aerial images. The process of building detection is carried out in a hierarchical manner. Line segments are first grouped to form vertices, which are then grouped to form edges. Edges are composed into edge rings. Shadow analysis on closed rings is used to make roof hypotheses. All the elements in the hierarchy are represented by frames. A search scheme based on an ATMS is used to deal with the ambiguities in this hierarchical grouping process