3.7.201. Quadtree
Denotes that, for a given constraint, a quadtree can be used within its filtering algorithm. A quadtree is a hierarchical data structure based on the recursive decomposition of space. FigureΒ 3.7.53 illustrates the representation of a two-dimensional binary region (A) with a quadtree (C). A region is subdivided into quadrants, subquadrants, and so on (B), until blocks consist entirely of 1s or entirely of 0s.