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. If they do not have the same extent, the output normalized image will only contain only the area where both rasters overlap.

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 properties (Set, Get): INPUT_RASTER1, INPUT_RASTER2, OUTPUT_RASTER_URI

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

INPUT_RASTER1 (required)

Specify a base raster for radiometric normalization. It applies the necessary gains and offsets to INPUT_RASTER2.

INPUT_RASTER2 (required)

Specify a second raster for radiometric normalization. INPUT_RASTER1 and INPUT_RASTER2 can have different map projections; in this case, reprojection and resampling are handled as follows:

INPUT_RASTER1 establishes the base projection for INPUT_RASTER2. The overlap of the two inputs is the area that is included in the analysis.
If the files use different pixel sizes, the input file with the lower resolution is resampled to use the higher resolution of the other input file.

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.

Version History

ENVI 5.2

Introduced

API Version

4.2