ENVIROI::ClearPixels

The ClearPixels method clears all pixels from an ROI.

Example

; Launch the application

e = ENVI()

; Open the input file

file = Filepath('qb_boulder_msi', ROOT_DIR=e.Root_Dir, $

SUBDIRECTORY=['data'])

raster = e.OpenRaster(file)

view = e.GetView()

layer = view.CreateLayer(raster)

; Open and display the associated ROIs

file = Filepath('qb_boulder_roi.xml', ROOT_DIR=e.Root_Dir, $

SUBDIRECTORY=['data'])

rois = e.OpenRoi(file)

numRois = N_Elements(rois)

roiLayers = Objarr(numRois)

FOR i=0, N_Elements(rois)-1 DO $

roiLayers[i] = layer.AddRoi(rois[i])

; Clear the pixels

rois[0].ClearPixels,spatialref=raster.spatialref

Syntax

ENVIROI.ClearPixels [, Keywords=value]

Arguments

None

Keywords

ERROR

Set this keyword to a named variable that will contain any error message issued during execution of this routine. If no error occurs, the ERROR variable will be set to a null string (''). If an error occurs and the routine is a function, then the function result will be undefined.

When this keyword is not set and an error occurs, ENVI returns to the caller and execution halts. In this case, the error message is contained within !ERROR_STATE and can be caught using IDL's CATCH routine. See IDL Help for more information on !ERROR_STATE and CATCH.

See Manage Errors for more information on error handling in ENVI programming.

SPATIALREF

Set the ENVIRaster reference that establishes the coordinate system reference for the pixel locations contained in the data. This keyword is not required; however, if it is not specified, ENVI will be unable to reproject the ROI pixels correctly.

Version History

ENVI 5.1

Introduced

API Version

4.2