LabelEntropyTexture Task

This task computes first-order entropy texture metrics on the label bands of a rank-strength-texture raster. These metrics are useful for cloud detection and feature extraction.

The virtual raster associated with this task is ENVILabelEntropyTextureRaster.

Example

This example computes label entropy texture from a multispectral raster and displays the first label entropy band.

; 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)

; Get the task from the catalog of ENVITasks

Task = ENVITask('LabelEntropyTexture')

; Define inputs

Task.INPUT_RASTER = Raster

; Run the task

Task.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, Task.OUTPUT_RASTER

; Display each band of the entropy image in a separate view

View1 = e.GetView()

Layer1 = View1.CreateLayer(Task.OUTPUT_RASTER, BANDS=[0], $

  NAME='Label entropy for band 1')

View2 = e.CreateView()

Layer2 = View2.CreateLayer(Task.OUTPUT_RASTER, BANDS=[1], $

  NAME='Label entropy for band 2')

View3 = e.CreateView()

Layer3 = View3.CreateLayer(Task.OUTPUT_RASTER, BANDS=[2], $

  NAME='Label entropy for band 3')

View4 = e.CreateView()

Layer4 = View4.CreateLayer(Task.OUTPUT_RASTER, BANDS=[3], $

  NAME='Label entropy for band 4')

; Create a geographic and zoom link for all views

View1.GeoLink, /LINK_ALL, /ZOOM_LINK

Syntax

Result = ENVITask('LabelEntropyTexture')

Input parameters (Set, Get): INPUT_RASTER, KERNEL_SIZE, 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

INPUT_RASTER (required)

Specify the input ENVIRaster. This routine accepts an image with any number of bands.

KERNEL_SIZE (optional)

Specify a two-element array [n,m] as the kernel size, where n is the number of columns and m is the number of rows. The values must be odd and at least 3, for example [3,3].

OUTPUT_RASTER_URI (optional)

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

If you set this parameter to an asterisk symbol (*), the output raster will be virtual and not written to disk.
If you do not specify this parameter, or set it to an exclamation symbol (!), a temporary file will be created.
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.