Deriving topological relations between regions from direction relations

The integration of topological and direction relations plays an important role in many applications, like spatial databases and pictorial retrieval systems. The method for deriving composition of binary topological relations cannot always yield unique or interesting results. Therefore, to integrate efficiently topological and direction relations, some new mechanisms are required to derive topological relations from direction cases when the above situations occur. This paper presents the computation methods for deriving topological relations from direction relations. The methods fall into two categories: the derivation of topological relations from one direction relation and two direction relations. Our methods can provide topological information when topological relations are unavailable, or more precise results are expected. Thus they are helpful in the integration of the calculi for topological and direction relations.