GBDX

ENVI® ISODATA Classification

This task is used to identify areas of spectral similarity within the input raster. The unsupervised classifier will produce a raster with classification classes matching the input number of classes.

GBDX Registered Name: ENVI_ISODATAClassification
Provider: Harris Geospatial Solutions

Imagery Examples

Before: WorldView 2 image after AOP correction

Before: WorldView 2 image after AOP correction

After: WorldView 2 image after ISODATA classification

After: WorldView 2 image after ISODATA classification

Quickstart

This is a workflow example for basic processing.

# Quickstart Example running the task name.

# Initialize the Environment.
from os.path import join, split
from gbdxtools import Interface
gbdx = Interface()

tasks = []
output_location = 'ENVI/ISODATAClassification'

cat_id = '105001000672E000'

# Image Auto ordering task parameters
order = gbdx.Task("Auto_Ordering")
order.inputs.cat_id = cat_id
order.impersonation_allowed = True
order.persist = True
order.timeout = 36000
tasks += [order]

# Image AOP task parameters
aop = gbdx.Task("AOP_Strip_Processor")
aop.inputs.data = order.outputs.s3_location.value
aop.inputs.bands = 'MS'
aop.inputs.enable_dra = False
aop.outputs.data.persist = True
aop.outputs.data.persist_location = output_location+'/aop'
aop.timeout = 36000
tasks += [aop]

# Create an ISODATA classification
envi_isodata = gbdx.Task("ENVI_ISODATAClassification")
envi_isodata.inputs.input_raster = aop.outputs.data.value
tasks += [envi_isodata]

workflow = gbdx.Workflow(tasks)
workflow.savedata(
    envi_isodata.outputs.output_raster_uri, location=output_location
)

workflow.execute()

Inputs

The following table lists all ENVI_ISODATAClassification 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 unsupervised classification. -- 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
change_threshold_percent False 2.0 string The change threshold percentage that determines when to complete the classification. When the percentage of pixels that change classes during an iteration is less than the threshold value, the classification completes. -- Value Type: DOUBLE -- Default Value: 2.0
number_of_classes False 5 string The requested number of classes to generate. -- Value Type: UINT -- Default Value: 5
iterations False 10 string The maximum iterations to perform. If the change threshold percent is not met before the maximum number of iterations is reached, the classification completes. -- Value Type: UINT -- Default Value: 10
output_raster_uri_filename False N/A string Specify a string with the fully-qualified path and filename for OUTPUT_RASTER. -- Value Type: STRING

Outputs

The following table lists all ENVI_ISODATAClassification 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 for OUTPUT_RASTER. -- 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® ISODATA Classification.

Contact

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

ENVI® ISODATA Classification

This task is used to identify areas of spectral similarity within the input raster. The unsupervised classifier will produce a raster with classification classes matching the input number of classes.

GBDX Registered Name: ENVI_ISODATAClassification
Provider: Harris Geospatial Solutions