Soft-linked quadtree: a cascaded ring structure using flexible linkage concept

The quadtree is a variant of the maximal block representation scheme. The author introduces the concept of flexible linkage and a modular ring structure. A soft-linked quadtree can be put together by various admissable permutations of three rings. Each ring consists of two nodes with uniform and/or mixed label. Each node, in contrast to a conventional quadtree, has only a probabilistic affiliation to various segments of an image. Moreover, the links between father and son nodes are soft and characterized by a branch strength. All nodes have children; the degree of mutual attachment is the variable. The presence of soft links gives rise to an up projection effect whereby the classification of children impacts the ancestor´s original label. This impact is modeled as a recursive relationship between all nodal state probabilities, branch strengths and tree depth. The implication of this approach for some existing quadtree-based algorithm is discussed