This task performs the Mixture Tuned Target-Constrained Interference-Minimized Filter (MTTCIMF) target analysis.
Example
This example performs the following steps:
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Opens an AVIRIS hyperspectral image subset.
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Runs a forward minimum noise transform (MNF) to reduce noise in the data.
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Defines three regions of interest (ROIs), each containing nine pixels of a common material.
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Retrieves the spectra from the ROIs and uses their means as targets for Mixture Tuned Target-Constrained Interference-Minimized Filter.
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Runs the MTTCIMF task, which performs mixture tuned target-constrained interference-minimized filtering.
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Displays the result. To see all of the bands, open the Data Manager.
e = ENVI()
File = Filepath('AVIRISReflectanceSubset.dat', $
SUBDIR=['data', 'hyperspectral'], $
ROOT_DIR=e.Root_Dir)
Raster = e.OpenRaster(File)
Task = ENVITask('ForwardMNFTransform')
Task.INPUT_RASTER = Raster
Task.Execute
Subset = ENVISubsetRaster(Task.OUTPUT_RASTER, BANDS=LINDGEN(25))
nSpectra = 9d
roi1 = ENVIROI(NAME='Green Field')
pixelAddr1 = [[77,182],[78,182],[79,182], $
[77,183],[78,183],[79,183], $
[77,184],[78,184],[79,184]]
roi1.AddPixels, pixelAddr1, SPATIALREF=Subset.SPATIALREF
roi2 = ENVIROI(NAME='Soil')
pixelAddr2 = [[386,285],[387,285],[388,285], $
[386,286],[387,286],[388,286], $
[386,287],[387,287],[388,287]]
roi2.AddPixels, pixelAddr2, SPATIALREF=Subset.SPATIALREF
roi3 = ENVIROI(NAME='Ground')
pixelAddr3 = [[296,326],[297,326],[298,326], $
[296,327],[297,327],[298,327], $
[296,328],[297,328],[298,328]]
roi3.AddPixels, pixelAddr3, SPATIALREF=Subset.SPATIALREF
spectra1 = Subset.GetData(ROI=roi1)
mean1 = Total(spectra1,1) / nSpectra
spectra2 = Subset.Getdata(ROI=roi2)
mean2 = Total(spectra2,1) / nSpectra
spectra3 = Subset.GetData(ROI=roi3)
mean3 = Total(spectra3,1) / nSpectra
targets = [[mean1],[mean2],[mean3]]
Task = ENVITask('MixtureTunedTargetConstrainedInterferenceMinimizedFilter')
Task.INPUT_RASTER = Subset
Task.TARGET = targets
Task.Execute
dataColl = e.Data
dataColl.Add, Task.OUTPUT_RASTER
View = e.GetView()
Layer = View.CreateLayer(Task.OUTPUT_RASTER)
Syntax
Result = ENVITask('MixtureTunedTargetConstrainedInterferenceMinimizedFilter')
Input parameters (Set, Get): BACKGROUND, BACKGROUND_THRESHOLD, COVARIANCE, INPUT_RASTER, NAMES, OUTPUT_RASTER_URI, REGULARIZATION_METHOD, REGULARIZATION_TOLERANCE, TARGET, USE_SUBSPACE_BACKGROUND
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
BACKGROUND (optional)
Specify the background spectra. It is a floating-point array. The array size is [number of bands, number of background spectra]. If not defined, at least two target spectra are needed.
BACKGROUND_THRESHOLD (optional)
This is a float value indicating the fraction of the background in the anomalous image to use when calculating statistics using subspace background. It ranges from 0.500 to 1.000 (the entire image), with the default 0.9.
COVARIANCE (optional)
Specify an array that is the covariance matrix of the input bands. The array size must be [number of bands, number of bands].
INPUT_RASTER (required)
Specify an input raster to process.
NAMES (optional)
Specify an array of target names. The array size must be [number of targets].
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.
REGULARIZATION_METHOD (optional)
Specify a method for regularizing the autocorrelation matrix:
- Diagonal: Diagonal loading, increasing all singular values by the tolerance value.
- Dominant: Dominant mode rejection, setting singular values less than the tolerance value to their mean.
- None: No regularization is used.
- Shrink: Shrinkage of singular values based on the tolerance value.
- Threshold: Singular values less than the tolerance value are set to the tolerance value.
- Truncate (default): Singular values less than the tolerance value are set to zero.
REGULARIZATION_TOLERANCE (optional)
Specify the tolerance value to use for matrix regularization. If not set, the following values will be used based on the regularization method
- Diagonal: Ten times the smallest nonzero singular value.
- Dominant: The value prescribed by Gavish & Donoho.
- None: N/A
- Shrink: The Oracle Approximating Shrinkage (OAS) estimator.
- Threshold: The largest singular value times the machine precision.
- Truncate (default): The largest singular value times the machine precision.
TARGET (required)
Specify the target spectra. It is a floating-point array. The array size is [number of bands, number of target spectra].
USE_SUBSPACE_BACKGROUND (optional)
Specify whether to use subspace background in statistics calculation.
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 6.0 |
Introduced |
ENVI 6.2 |
Added the NAMES, REGULARIZATION_METHOD, and REGULARIZATION_TOLERANCE parameters.
|
See Also
ENVITask