MARCO - MAP RETRIEVAL BY CONTENT

A system named MARCO (denoting MAp Retrieval by COntent) that is used for the acquisition, storage, indexing, and retrieval of map images is presented. The input to MARCO are raster images of separate map layer s and raster images of map composites. A legend-driven map interpretat ion system converts map layer images from their physical representatio n to their logical representation. This logical representation is then used to automatically index both the composite and the layer images. Methods for incorporating logical and physical layer images as well as composite images into the framework of a relational database manageme nt system are described. Indices are constructed on both the contextua l and the spatial data thereby enabling efficient retrieval of layer a nd composite images based on contextual as well as spatial specificati ons. Example queries and query processing strategies using these indic es are described. The user interface is demonstrated via the execution of an example query. Results of an experimental study on a large amou nt of data are presented. The system is evaluated in terms of accuracy and in terms of query execution time.