Donna J. Peuquet | Geology Reports

USGS1982

A hybrid structure for the storage and manipulation of very large spatial data sets

The map data input and output problem for geographic information systems is rapidly diminishing with the increasing availability of mass digitizing, direct spatial data capture and graphics hardware based on raster technology. Although a large number of efficient raster-based algorithms exist for performing a wide variety of common tasks on these data, there are a number of procedures which are more efficiently performed in vector mode or for which raster mode equivalents of current vector-based techniques have not yet been developed. This paper presents a hybrid spatial data structure, named the ?vaster' structure, which can utilize the advantages of both raster and vector structures while potentially eliminating, or greatly reducing, the need for raster-to-vector and vector-to-raster conversion. Other advantages of the vaster structure are also discussed.

Open-File Report↗

USGS1981

An examination of techniques for reformatting digital cartographic data. Part 2: The vector-to raster process.

Current graphic devices suitable for high-speed computer input and output of cartographic data are tending more and more to be raster-oriented, such as the rotating drum scanner and the color raster display. However, the majority of commonly used manipulative techniques in computer-assisted cartography and automated spatial data handling continue to require that the data be in vector format. The current article is the second part of a two-part paper that examines the state of the art in these conversion techniques. - from Author

Cartographica: The International Journal for Geogr↗

USGS1981

An examination of techniques for reformatting digital cartographic data/part 1: The raster-to- vector process.

Current graphic devices suitable for high-speed computer input and output of cartographic data are tending more and more to be raster-oriented, such as the rotating drum scanner and the color raster display. However, the majority of commonly used manipulative techniques in computer-assisted cartography and automated spatial data handling continue to require that the data be in vector format. This situation has recently precipitated the requirement for very fast techniques for converting digital cartographic data from raster to vector format for processing, and then back into raster format for plotting. The current article is part one of a two-part paper concerned with examining the state-of-the-art in these conversion techniques. In part one, algorithms to perform all phases of the raster-to-vector process are systematically outlined, and then compared in general terms. Examples of existing implementations of the raster-to-vector process are also described and evaluated. Part two will outline and compare algorithms to perform the reverse process, vector-to-raster conversion. Part two will also discuss raster-to-vector and vector-to-raster conversion as an integrated process.

Cartographica: The International Journal for Geogr↗