BufferZone Task

This task creates a buffer zone image from a classification image. Each pixel in the output image is the nearest distance, in pixels, from any classified pixel specified by CLASS_NAME.

Example

; Start the application

e = ENVI()

; Open an input raster and vector

File1 = Filepath('qb_boulder_msi', Subdir=['data'], $

Root_Dir=e.Root_Dir)

Raster = e.OpenRaster(File1)

File2 = Filepath('qb_boulder_msi_vectors.shp', Subdir=['data'], $

Root_Dir=e.Root_Dir)

Vector = e.OpenVector(File2)

; Get training statistics

StatTask = ENVITask('TrainingClassificationStatistics')

StatTask.INPUT_RASTER = Raster

StatTask.INPUT_VECTOR = Vector

StatTask.Execute

; Get the task from the catalog of ENVITasks

ClassTask = ENVITask('SpectralAngleMapperClassification')

; Define inputs

ClassTask.INPUT_RASTER = Raster

ClassTask.MEAN = StatTask.MEAN

; Run the task

ClassTask.Execute

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

DataColl = e.Data

; Add the output to the Data Manager

DataColl.Add, ClassTask.OUTPUT_RASTER

; Display the result

View = e.GetView()

Layer = View.CreateLayer(ClassTask.OUTPUT_RASTER)

; Run the buffer zonetask

BufferZoneTask = ENVITask('BufferZone')

BufferZoneTask.INPUT_RASTER = ClassTask.OUTPUT_RASTER

BufferZoneTask.CLASS_NAME = 'Class 1'

BufferZoneTask.OUTPUT_DATA_TYPE = 'Float'

BufferZoneTask.MAXIMUM_DISTANCE = 20

BufferZoneTask.Execute

; Add the output to the Data Manager

DataColl.Add, BufferZoneTask.OUTPUT_RASTER

; Display the result

Layer2 = View.CreateLayer(BufferZoneTask.OUTPUT_RASTER)

Syntax

Result = ENVITask('BufferZone')

Input parameters (Set, Get): CLASS_NAME, INPUT_RASTER, MAXIMUM_DISTANCE, OUTPUT_DATA_TYPE, OUTPUT_RASTER_URI

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

CLASS_NAME (required)

Specify an array with the names of the classes around which to compute the buffer zone.

INPUT_RASTER (required)

Specify a classification raster.

MAXIMUM_DISTANCE (optional)

Specify a long integer representing the maximum distance (in pixels) for the buffer zone.

The default value is 10000.

OUTPUT_DATA_TYPE (optional)

Specify the output data type.

Integer (default)
Float

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.