GeoJSONToROI Task

This task converts GeoJSON features to one or more regions of interest (ROIs).

GeoJSON is a geospatial format based on JSON code that is used for encoding geographic data structures. For more information, see the GeoJSON Format Specification. Also see the GeoJSONLint web page for example code and for tools that validate GeoJSON code.

Example

This example creates multiple ROIs from multiple GeoJSON features:

; Start the application

e = ENVI()

 

; Open a GeoJSON file

File = Filepath('boulder_multiple_features.json', $

  Subdir=['data', 'geojson'], $

  Root_Dir=e.Root_Dir)

GeoJSON = ENVIGeoJSON(JSON_Parse(File))

 

; Open an associated raster file

File = Filepath('qb_boulder_msi', Subdir=['data'], $

  Root_Dir=e.Root_Dir)

Raster = e.OpenRaster(File)

 

; Get the task from the catalog of ENVITasks

task = ENVITask('GeoJSONToROI')

 

; Define task inputs

task.Input_GeoJSON = GeoJSON

 

; Run the task

task.Execute

 

; Display the result

view = e.GetView()

layer = view.CreateLayer(Raster)

rois = task.OUTPUT_ROI

roiLayers = OBJARR(N_ELEMENTS(rois))

FOR i=0, N_ELEMENTS(rois)-1 DO roiLayers[i] = layer.AddROI(rois[i])

Syntax

Result = ENVITask('GeoJSONToROI')

Input properties (Set, Get): INPUT_GEOJSON, OUTPUT_ROI_URI

Output properties (Get only): OUTPUT_ROI

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:

AddParameter

Execute

Parameter

ParameterNames

RemoveParameter

Properties

This task inherits the following properties from ENVITask:

COMMUTE_ON_DOWNSAMPLE

COMMUTE_ON_SUBSET

DESCRIPTION

DISPLAY_NAME

NAME

REVISION

TAGS

This task also contains the following properties:

INPUT_GEOJSON (required)

Specify an input GeoJSON object. You can add name and color properties to each Feature object. See the example code in this topic.

To ensure properly validated GeoJSON code, refer to the GeoJSONLint web page.

OUTPUT_ROI

This is a reference to the output ROI. The output can be an array of ROIs if the input GeoJSON contains a Feature Collection.

OUTPUT_ROI_URI (optional)

Specify a string with the fully-qualified path and filename for OUTPUT_ROI.

Version History

ENVI 5.3

Introduced

ENVI 5.5.3

OUTPUT_ROI can be an array of ROIs

API Version

4.2

See Also

ENVITask, ExtractGeoJSONFromFile Task, ENVIGeoJSON, ENVIROI