GBDX

ENVI® Pixel Purity Index

This task performs a Pixel Purity Index calculation on an input MNF result.
GBDX Registered Name: ENVI_PixelPurityIndex
Provider: Harris Geospatial Solutions

Inputs

The following table lists all ENVI_PixelPurityIndex inputs.
Mandatory (optional) settings are listed as Required = True (Required = False).

Name Required Default Valid Values Description
file_types False N/A string GBDX Option. Comma seperated list of permitted file type extensions. Use this to filter input files -- Value Type: STRING[*]
input_raster True N/A See ENVIRASTER input type Specify a raster on which to perform the pixel purity index calculation. -- Value Type: ENVIRASTER
input_raster_format False N/A See ENVIRASTER input type Provide the format of the image, for example: landsat-8. -- Value Type: STRING
input_raster_band_grouping False N/A See ENVIRASTER input type Provide the name of the band grouping to be used in the task, ie - panchromatic. -- Value Type: STRING
input_raster_filename False N/A See ENVIRASTER input type Provide the explicit relative raster filename that ENVI will open. This overrides any file lookup in the task runner. -- Value Type: STRING
input_raster_raw_output False False See ENVIRASTER input type Provide True to output an ENVI Binary instead of a tif. -- Value Type: STRING
iterations False 1000 string Specify the number of iterations for the pixel purity index calculation. -- Value Type: ULONG -- Default Value: 1000
threshold False 2.5 string Specify the threshold factor in data units for pure pixel selection. -- Value Type: DOUBLE -- Default Value: 2.5
resize_factor False 1.0 string Specify a resize factor to subsample the input raster so that the entire file will fit comfortably into memory. -- Value Type: DOUBLE -- Default Value: 1.0
output_raster_uri_filename False N/A string Specify a string with the fully qualified path and filename of the output raster. -- Value Type: STRING

Outputs

The following table lists all ENVI_PixelPurityIndex outputs.
Mandatory (optional) settings are listed as Required = True (Required = False).

Name Required Default Valid Values Description
task_meta_data False N/A directory GBDX Option. Output location for task meta data such as execution log and output JSON
output_histogram False N/A string Specify an array to receive the histogram of the pixel purity index result. -- Value Type: LONGARRAY
output_raster_uri True N/A directory Output of the output raster. -- Value Type: ENVIURI

Output structure

The output_histogram file will be written to the specified S3 Customer Account Location.The output_raster_uri file will be written to the specified S3 Customer Account Location.

Background

For additional background information on this task please refer to the Harris Geospatial ENVI documentation and
ENVI® Pixel Purity Index.

Contact

If you have any questions or issues with this task, please contact gbdx-support@digitalglobe.com.