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 parameters (Set, Get): INPUT_RASTER, OUTPUT_RASTER_URI, THRESHOLD

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 raster to threshold.

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.

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.

Output Parameters


OUTPUT_RASTER

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

Methods


Execute

Parameter

ParameterNames

Properties


DESCRIPTION

DISPLAY_NAME

NAME

REVISION

TAGS

Version History


ENVI 5.3

Introduced

ENVI 5.5

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

See Also


ENVITask, ENVILowClipRaster, ENVIHighClipRaster, HighClipRaster Task