SpectralSmoothing Task

This task applies the Savitsky-Golay smoothing filter to smooth noisy spectral signatures.

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)

; Get the task from the catalog of ENVITasks

Task = ENVITask('SpectralSmoothing')

; Define inputs

Task.INPUT_RASTER = Raster

; Run the task

Task.Execute

; Add the output to the Data Manager

e.Data.Add, Task.OUTPUT_RASTER

; Display the result

View = e.GetView()

Layer = View.CreateLayer(Task.OUTPUT_RASTER)

Syntax

Result = ENVITask('SpectralSmoothing')

Input properties (Set, Get): DEGREE_OF_POLY, INPUT_RASTER, ORDER_OF_DERIVATIVE, OUTPUT_RASTER_URI, PIXELS_TO_LEFT, PIXELS_TO_RIGHT

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:

Properties

This task inherits the following properties from ENVITask:

COMMUTE_ON_DOWNSAMPLE

DEGREE_OF_POLY (optional)

Specify an integer less than the filter width (sum of PIXELS_TO_LEFT and PIXELS_TO_RIGHT). Typical values are 2 to 4.

The default value is 2.

INPUT_RASTER (required)

Specify the raster on which to perform spectral smoothing.

ORDER_OF_DERIVATIVE (optional)

Specify an integer for the smoothed order derivative of the signal.

The default value is 0.

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 of the associated OUTPUT_RASTER. If you do not specify this property, or set it to an exclamation symbol (!), a temporary file will be created.

PIXELS_TO_LEFT (optional)

Specify the number of pixels to the left of the data point. Larger values produce a smoother result at the expense of flattening sharp peaks.

The default value is 1.

PIXELS_TO_RIGHT (optional)

Specify the number of pixels to the right of the data point. Larger values produce a smoother result at the expense of flattening sharp peaks.