@techreport{R-92-33, TITLE = {Generation of Multi-Resolution Maps}, AUTHOR = {Jonas Persson}, YEAR = {1992}, NUMBER = {R-92-33}, INSTITUTION = ida, ADDRESS = idaaddr, ABSTRACTURL = {/publications/cgi-bin/tr-fetch.pl?r-92-33+abstr}, ABSTRACT = {In geographical information systems (GIS), the need for hierarchically organized data structures has evolved. The reason for this stems from the fact that the map information usually is extremely large and that low resolution maps in most applications require less heavy computations than maps represented in higher resolutions. Hierarchical spatial data structures for generation of maps in lower resolutions already exist, e g quad-trees and resolution pyramids. Many other spatial data structures that are non-hierarchical do not permit the generation of resolution hierarchies like the two above. One such structure is the run-length code (RLC), which has many powerful advantages that make the structure feasible in a GIS. For that reason a method for generation of resolution hierarchies based on RLC is needed. In this work an approach to the problem of generating a resolution hierarchy from RLC is described and discussed. A generalisation method based on recursive polygon approximation is described in detail.}, IDANR = {LiTH-IDA-R-92-33}, NOTE = {Awarded the prize " Lilla Polhemspriset" 1992}