A Pictorial Language for the Retrieval of Spatial Relations from Image Databases
Dimitrios Papadias, Timos Sellis · 1994
The paper describes a Pictorial Query-By-Example (PQBE) aimed at the retrieval of direction relations from Image Databases. PQBE incorporates several features such as object, image and relation retrieval, union, intersection etc. Unlike verbal query languages it does not presume knowledge of keywords for spatial relations on behalf of the user, nor familiarity with database models, but complex spatial conditions are expressed in a straightforward manner. Furthermore, with the incorporation of some additional features, such as topological relations, distances and class retrieval, PQBE can be used as an intuitive GIS interface, independently of the underlying representation. 1. INTRODUCTION The representation and retrieval of direction relations (e.g., north, northeast etc.) has received a lot of attention in a number of application domains related to large-scale and small-scale spaces (Peuquet, 1986), (Freksa, 1992) (Frank, 1994). Several structures, such as symbolic images, 2D string...