RadiometricNormalization Task

This task creates a radiometric normalized image from two rasters. Radiometric normalization minimizes differences between two images that are caused by inconsistencies of acquisition conditions, such as changes caused by different atmospheric and illumination conditions.

Both input rasters must have the same spatial dimensions. The task was designed for rasters that cover the same geographic extent.

Example

; Start the application

e = ENVI()

; Open two input files

File1 = Filepath('world_dem', Subdir=['classic', 'data'], $

  Root_Dir=e.Root_Dir)

Raster1 = e.OpenRaster(File1)

File2 = Filepath('egm96_global.dat', $

  Subdir=['classic', 'data'], Root_Dir=e.Root_Dir)

Raster2 = e.OpenRaster(File2)

; Process a spectral subset

subRaster1 = ENVISubsetRaster(Raster1, BANDS=0)

; Get the task from the catalog of ENVITasks

Task = ENVITask('ImageIntersection')

; Define inputs

Task.INPUT_RASTER1 = subRaster1

Task.INPUT_RASTER2 = Raster2

; Run the task

Task.Execute

; Get the task from the catalog of ENVITasks

RadNormTask = ENVITask('RadiometricNormalization')

; Define inputs

RadNormTask.INPUT_RASTER1=Task.OUTPUT_RASTER1

RadNormTask.INPUT_RASTER2=Task.OUTPUT_RASTER2

; Run the task

RadNormTask.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, RadNormTask.OUTPUT_RASTER

; Display the result

View = e.GetView()

Layer = View.CreateLayer(RadNormTask.OUTPUT_RASTER)

Syntax

Result = ENVITask('RadiometricNormalization')

Input parameters (Set, Get): INPUT_RASTER1, INPUT_RASTER2, METHOD, 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_RASTER1 (required)

Specify a raster that will provide the reference for radiometric normalization.

INPUT_RASTER2 (required)

Specify a raster that will undergo radiometric normalization to INPUT_RASTER1.

METHOD (optional)

Specify the normalization method to use:

Standard: (default) The output raster will have the same spectral mean and standard deviation as the reference raster.
Covariance Equalization: The output raster will have the same spectral covariance as the reference raster.
Linear Estimation: The output raster will be the minimum mean squared error (MMSE) linear estimate based on the spectral cross-covariance between the two input rasters.

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.