Cartographic objects in a multi-scale data structure

GIS need a function to draw sketches quickly and in arbitrary scales. We propose a multiscale hierarchical spatial model for cartographic data. Objects are stored with increasing detail and can be used to compose a map at a particular scale. This results in a multi-scale cartographic forest when applied to cartographic mapping. The structure of the multi-scale forest is explained. It is based on a trade-off between storage and computation. Methods to select cartographic objects for rendering are based on the principle of equal information density.