Quadtree-based representations of grid-oriented data

Two modifications of quadtrees are described for representations of grid-oriented data. First, the extended forms of quadtree are presented, which allow homogeneous coverage of the relevant parts (or even the whole) of pictures with equal sized blocks of required dimensions being equivalent with a grid. Then a special form of quadtree is introduced enabling the storage of multi-valued data. These hierarchical forms enable multiresolution approaches when dealing with such grid-oriented data as terrain information, potentials, approximate Voronoi diagrams, but also spatial object models, etc. The data are stored directly into the matrix representation of the corresponding quadtree. More examples of application are included.