GBDX

ENVI® SAM Image Difference

This task performs difference analysis by measuring the spectral angle for every pixel. It determines the similarity between two rasters by calculating the angle between the spectra and treating them as vectors in a space with dimensionality equal to the number of bands.
GBDX Registered Name: ENVI_SAMImageDifference
Provider: Harris Geospatial Solutions

Inputs

The following table lists all ENVI_SAMImageDifference 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_raster1 True N/A See ENVIRASTER input type Specify a multi-band raster representing the earliest time. -- Value Type: ENVIRASTER
input_raster1_format False N/A string Provide the format of the image, for example: landsat-8. -- Value Type: STRING
input_raster1_band_grouping False N/A string Provide the name of the band grouping to be used in the task, ie - panchromatic. -- Value Type: STRING
input_raster1_filename False N/A string Provide the explicit relative raster filename that ENVI will open. This overrides any file lookup in the task runner. -- Value Type: STRING
input_raster1_raw_output False False See ENVIRASTER input type Provide True to output an ENVI Binary instead of a tif. -- Value Type: STRING
input_raster2 True N/A See ENVIRASTER input type Specify a multi-band raster representing the latest time. -- Value Type: ENVIRASTER
input_raster2_format False N/A string Provide the format of the image, for example: landsat-8. -- Value Type: STRING
input_raster2_band_grouping False N/A string Provide the name of the band grouping to be used in the task, ie - panchromatic. -- Value Type: STRING
input_raster2_filename False N/A string Provide the explicit relative raster filename that ENVI will open. This overrides any file lookup in the task runner. -- Value Type: STRING
input_raster2_raw_output False False See ENVIRASTER input type Provide True to output an ENVI Binary instead of a tif. -- Value Type: STRING
output_raster_uri_filename False N/A string 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. -- Value Type: STRING

Outputs

The following table lists all ENVI_SAMImageDifference 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_raster_uri True N/A directory Output 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. -- Value Type: ENVIURI

Output structure

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® SAMImage Difference.

Contact

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