This task creates a new raster where values below a threshold are set to the threshold.

The virtual raster associated with this task is ENVILowClipRaster.

Example


In this example:

  • Pixel values less than or equal to 250.0 in Band 1 are set to 250.0
  • Pixel values less than or equal to 360.0 in Band 2 are set to 360.0
  • Pixel values less than or equal to 270.0 in Band 3 are set to 270.0
  • Pixel values less than or equal to 360.0 in Band 4 are set to 360.0
; 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('LowClipRaster')
 
; Define inputs
Task.INPUT_RASTER = Raster
Task.THRESHOLD = [250., 360., 270., 360.]
 
; 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 the result
View = e.GetView()
Layer = View.CreateLayer(Task.OUTPUT_RASTER)

Syntax


Result = ENVITask('LowClipRaster')

Input properties (Set, Get): INPUT_RASTER, OUTPUT_RASTER_URI, THRESHOLD

Output properties (Get only): OUTPUT_RASTER

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

Methods


This task inherits the following methods from ENVITask:

AddParameter

Execute

Parameter

ParameterNames

RemoveParameter

Properties


This task inherits the following properties from ENVITask:

COMMUTE_ON_DOWNSAMPLE

COMMUTE_ON_SUBSET

DESCRIPTION

DISPLAY_NAME

NAME

REVISION

TAGS

This task also contains the following properties:

INPUT_RASTER (required)

Specify the raster to threshold.

OUTPUT_RASTER

This is a reference to the output raster of filetype ENVI.

OUTPUT_RASTER_URI (optional)

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

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

THRESHOLD (required)

Specify an array of threshold values (one per band). If the source raster only has one band, specify an array with one element.

Version History


ENVI 5.3

Introduced

ENVI 5.5

OUTPUT_RASTER_URI now supports '*', which allows OUTPUT_RASTER to be virtual output.

API Version


4.2

See Also


ENVITask, ENVILowClipRaster, ENVIHighClipRaster, HighClipRaster Task