An overview of the coverage Generalization toolset

This topic applies to ArcInfo only.

Generalization tools derive coverages with less detail and complexity for analysis and representation at reduced scales or for special purposes.

They maintain the geographic characteristics and integrity of the data and meet cartographic specifications. For example, coastlines or boundaries can be simplified by removing the small fluctuations from them without destroying their essential shapes; features that are too close to each other can be aggregated into larger area features.

Although generalization is a complicated and subjective task and the rules are not well-defined, a set of tools, such as Simplify Line Or Polygon and Aggregate Polygons, has been implemented to automate the process and to meet common generalization requirements as much as possible. Where known limitations or unresolved issues exist, flags are added to the output to support quality inspection and postediting or postprocessing.

In general, you don't need to understand all the details about the techniques or algorithms used to set the parameters used by these tools; many of the numerical parameters are directly or closely related to spatial constraints, such as minimum distance or minimum size of the features, and the effects of changing the values are usually quite obvious.

Ideally, each Generalization operation should take all related or nearby features into account to avoid or resolve conflicts and maintain spatial relationships—this is called contextual generalization that involves multiple inputs. Each tool in this toolset is limited to dealing with one input at a time.

Tool	Description
Aggregate Polygons	Combines disjoint and adjacent polygons into new area features based on a distance.
Collapse Dual Lines To Centerline	Derives centerlines (single lines) from dual-line features, such as road casings, based on specified width tolerances.
Dissolve	Creates a new coverage by merging adjacent polygons, lines, or regions that have the same value for a specified item.
Eliminate	Merges the selected polygons with neighboring polygons if they have the largest shared border or the largest area.
Find Conflicts	Finds where simplified buildings overlap or are too close to each other, based on a specified distance.
Simplify Building	Simplifies the boundary or footprint of building polygons while maintaining their essential shape and size.
Simplify Line Or Polygon	Simplifies a line or a polygon boundary by removing small fluctuations or extraneous bends from it while preserving its essential shape.

Generalization toolset