org.geotools.process.raster

Class PolygonExtractionProcess

Object

PolygonExtractionProcess

All Implemented Interfaces:

RasterProcess

public class PolygonExtractionProcess
extends Object
implements RasterProcess

A process for raster to vector conversion. Regions of uniform value in an input GridCoverage2D are converted into Polygons by tracing the cell boundaries. Results are returned as a SimpleFeatureCollection in which each feature corresponds to a raster region with the boundary Polygon as its default geometry ("the_geom") and the value of the raster region cells as an attribute ("value").

Optionally, a list of classification ranges (Range objects) can be provided to pre-classify the input coverage values into intervals. Vectorizing can also be restricted to a sub-area of the coverage and/or a subset of raster values (by defining values to treat as no-data).

Since:

8.0

Author:

Simone Giannecchini, GeoSolutions

Constructor Summary

Constructors

Constructor and Description
PolygonExtractionProcess()

Method Summary

Modifier and Type	Method and Description
SimpleFeatureCollection	execute(GridCoverage2D coverage, Integer band, Boolean insideEdges, Geometry roi, Collection<Number> noDataValues, List<Range> classificationRanges, ProgressListener progressListener) Executes the raster to vector process.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PolygonExtractionProcess

public PolygonExtractionProcess()

Method Detail

execute

public SimpleFeatureCollection execute(GridCoverage2D coverage,
                                       Integer band,
                                       Boolean insideEdges,
                                       Geometry roi,
                                       Collection<Number> noDataValues,
                                       List<Range> classificationRanges,
                                       ProgressListener progressListener)
                                throws ProcessException

Executes the raster to vector process.

Parameters:

coverage - the input grid coverage

band - the coverage band to process; defaults to 0 if null

insideEdges - whether boundaries between raster regions with data values (ie. not NODATA) should be returned; defaults to true if null

roi - optional polygonal Geometry to define a sub-area within which vectorizing will be done

noDataValues - optional list of values to treat as NODATA; regions with these values will not be represented in the returned features; if null, 0 is used as the single NODATA value; ignored if classificationRanges is provided

classificationRanges - optional list of Range objects to pre-classify the input coverage prior to vectorizing; values not included in the list will be treated as NODATA; values in the first Range are classified to 1, those in the second Range to 2 etc.

progressListener - an optional listener

Returns:

a feature collection where each feature has a Polygon ("the_geom") and an attribute "value" with value of the corresponding region in either coverage or the classified coverage (when classificationRanges is used)

Throws:

ProcessException