Exploring the Effects of Vector to Raster and Raster to Vector Conversion

摘要

Spatial data can be represented in two formats: raster (grid cell) or vector(polygon). It is inevitable that conversion of the data between these two formats be essential to the best use of the data. Most geographic information systems (GIS) now provide software for such a conversion. The objective of the study was to evaluate the effects of data conversion on the accuracy of the resulting data layer. Simple shapes were chosen to document the results of the raster to vector and vector to raster conversion processes. These shapes included a square, a triangle (not aligned with the grid), a circle, a hole within the circle, and a non-convex shape. Error matrices were employed to represent the changes in area through the conversion process. A second set of data including a circle, a thin rectangle, and a wide rectangle were used to examine the effects of grid cell size on both presence/absence of a feature as well as maintaining the feature's shape. Finally, recommendations for continuing the work and its application to information derived from remotely sensed data were presented.