PercentThresholdClassification Task

This task segments the an image into anomalous and non-anomalous regions. The threshold should be set low enough to minimize false positives without omitting real anomalies.

Example

; 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)

; Run the anomaly detection task

AnomalyTask = ENVITask('RXAnomalyDetection')

AnomalyTask.INPUT_RASTER = Raster

AnomalyTask.Execute

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

DataColl = e.Data

; Add the anomaly detection output to the Data Manager

DataColl.Add, Task.OUTPUT_RASTER

; Display the result

View = e.GetView()

Layer = View.CreateLayer(AnomalyTask.OUTPUT_RASTER)

; Get the thresholding task from the catalog of ENVITasks

PercentThresholdTask = ENVITask('PercentThresholdClassification')

; Define inputs

PercentThresholdTask.INPUT_RASTER = AnomalyTask.OUTPUT_RASTER

; Run the task

PercentThresholdTask.Execute

; Add the output to the Data Manager

DataColl.Add, PercentThresholdTask.OUTPUT_RASTER

; Display the result

Layer2 = View.CreateLayer(PercentThresholdTask.OUTPUT_RASTER)

; Flicker between the unthresholded anomaly detection image

; and the threshold image

Portal = View.CreatePortal()

Portal.Animate, 2.0, /FLICKER

Syntax

Result = ENVITask('PercentThresholdClassification')

Input parameters (Set, Get): INPUT_RASTER, OUTPUT_RASTER_URI, THRESHOLD_PERCENT

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

INPUT_RASTER (required)

Specify a raster on which to segment the image into anomalous and non-anomalous regions.

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.