Efficient evaluation of spatial queries is an important issue in spatial database.Among spatial operations

spatial join is very useful

intersection being the most common predicate.The main objects of spatial joins are polygons and polylines

special for polylines

saving the direction of the polylines

and using different colors to represent different types of spatial join that the objects join with the cells.The new raster approximation is FourColor Directional Raster Signature(4CDRS).It is used as a filter i...