ClassificationAggregation Task

This task aggregates smaller class regions to a larger, adjacent region as part of the classification cleanup.

Example

The following example performs an unsupervised classification, followed by an aggregate operation.

; Start the application

e = ENVI()

; Open an input file

File = Filepath('qb_boulder_msi', Subdir=['data'], $

Root_Dir=e.Root_Dir)

Raster = e.OpenRaster(File)

; Create a classification ENVIRaster

ClassTask = ENVITask('ISODATAClassification')

ClassTask.INPUT_RASTER = Raster

ClassTask.Execute

; Get the collection of data objects currently available in the Data Manager

DataColl = e.Data

; Add the class image to the Data Manager

DataColl.Add, ClassTask.OUTPUT_RASTER

; Display the result

View = e.GetView()

Layer = View.CreateLayer(ClassTask.OUTPUT_RASTER)

; Run the aggregation task

AggregationTask = ENVITask('ClassificationAggregation')

AggregationTask.INPUT_RASTER = ClassTask.OUTPUT_RASTER

AggregationTask.Execute

; Add the output to the Data Manager

DataColl.Add, AggregationTask.OUTPUT_RASTER

; Display the result

Layer2 = View.CreateLayer(AggregationTask.OUTPUT_RASTER)

; Flicker between the original classification and the classification after

; aggregation

Portal = View.CreatePortal()

Portal.Animate, 2.0, /FLICKER

Syntax

Result = ENVITask('ClassificationAggregation')

Input parameters (Set, Get): INPUT_RASTER, MINIMUM_SIZE, OUTPUT_RASTER_URI, AGGREGATE_UNCLASSIFIED

Output parameters (Get only): OUTPUT_RASTER

Parameters marked as "Set" are those that you can set to specific values. You can also retrieve their current values any time. Parameters marked as "Get" are those whose values you can retrieve but not set.

Input Parameters

AGGREGATE_UNCLASSIFIED (optional)

Specify whether or not to treat unclassified pixels as a class that other pixels can be aggregated into. The default is true. Set to false to avoid aggregating into unclassified pixels.

INPUT_RASTER (required)

Specify a classification raster on which to perform aggregation.

MINIMUM_SIZE (optional)

Specify the aggregate minimum size in pixels. Regions with a size of this value or smaller are aggregated to an adjacent, larger region. The default value is 9.

OUTPUT_RASTER_URI (optional)

Specify a string with the fully qualified filename and path of the associated OUTPUT_RASTER.

If you do not specify this parameter, or set it to an exclamation symbol (!), ENVI creates a temporary file.
If you set it to the hash symbol (#), ENVI creates a file in the temporary directory, but this file will not be deleted when ENVI closes.