ENVIROI

This is a reference to an ROI object.

Example

; Launch the application

e = ENVI()

; Open an ENVIRaster

file = FILEPATH('qb_boulder_msi', ROOT_DIR=e.ROOT_DIR, $

  SUBDIRECTORY = ['data'])

raster = e.OpenRaster(file)

; Create an ROI

roi1 = ENVIROI(NAME='Region 1', COLOR='Blue')

; Print the ROI properties

Print, roi1

IDL prints:

ENVIROI <244676>

  COLOR = 0, 0, 255

  NAME = 'Region 1'

  N_DEFINITIONS = 0

See More Examples.

Syntax

Result = ENVIROI([, Keywords=value])

Methods

Properties

Properties can be set as keywords to functions during creation, or retrieved or changed using the "." notation after creation.

COLOR

Set this property to a string or RGB vector that specifies the color of the ROI. If this property is not set, then it will use a default color.

The following table lists the single characters that you can use as the color modifier in either the COLOR property or the Format string argument. You must use the lower-case character.

Color Name	Character
Blue	b
Green	g
Red	r
Cyan	c
Magenta	m
Yellow	y
Black	k
White	w

When setting the COLOR property, you can also use any of the string values defined by the !COLOR system variable, as shown in the following image:

NAME

Use this property to specify a named variable that contains a ROI name. If this property is not set, then it will use a default name that is currently not in use, starting with Region 1.

More Examples

This example shows how to get the properties of multiple ROI records within a single ROI file:

; Launch the application

e = ENVI()

; Open an ENVIRaster

file = FILEPATH('qb_boulder_msi', ROOT_DIR=e.ROOT_DIR, $

  SUBDIRECTORY = ['data'])

raster = e.OpenRaster(file)

; Open a multi-part ROI

ROIFile = FILEPATH('qb_boulder_roi.xml', $

  ROOT_DIR=e.ROOT_DIR, SUBDIRECTORY = ['data'])

rois = e.OpenROI(ROIFile)

; Print the ROI properties

For i=0, n_elements(rois)-1 do $

  Print, rois[i]

IDL prints:

ENVIROI <231489>

  COLOR                     = 240, 240,   0

  NAME                      = 'Disturbed Earth'

  N_DEFINITIONS             = 1

ENVIROI <231490>

  COLOR                     = 255,   0,   0

  NAME                      = 'Bright Roof'

  N_DEFINITIONS             = 1

ENVIROI <231491>

  COLOR                     = 29,  29, 255

  NAME                      = 'Water'

  N_DEFINITIONS             = 1

Also see How do I process the pixels within a region of interest (ROI)?

Version History

ENVI 5.1	Introduced
ENVI 5.3.1	Added Dehydrate method
ENVI 5.4	Added Hydrate method

API Version

4.2