Region representation: Boundary codes from quadtrees, Comm. ACM, vol.23, issue.3, pp.171-179, 1980. ,
Computing Perimeters of Regions in Images Represented by Quadtrees, IEEE Transactions on Pattern Analysis and Machine Intelligence, vol.3, issue.6, pp.683-68, 1981. ,
DOI : 10.1109/TPAMI.1981.4767171
The Quadtree and Related Hierarchical Data Structures, ACM Computing Surveys, vol.16, issue.2, pp.187-260, 1984. ,
DOI : 10.1145/356924.356930