ENVINITF::GetBandValue

The GetBandValue method retrieves the value of band fields from selected NITF or MIE4NITF image segments.

Example

; Start the application

e = ENVI(/HEADLESS)

; Open a NITF file

File = FILEPATH('MultiSegmentExample.ntf', ROOT_DIR=e.ROOT_DIR, $

  SUBDIRECTORY = ['data', 'NITFExamples'])

NITF = ENVINITF(File)

; Get the value of the ISUBCAT field

Print, NITF.GetBandValue('Image', 0, 'IREPBAND')

Result:

Syntax

Result = ENVINITF.GetBandValue(Type, Index, Field[, BAND_INDEX=value, ERROR=value])

Return Value

This method returns the value of a band segment field.

Arguments

Type

Specify a string with the segment type from which to retrieve band segment fields. Strings are not case-sensitive. The choices are:

Image

Or, specify the name of a MIE4NITF camera series; for example: series0, series1, etc.

Index

Specify an integer with the index number of a segment or a frame in a series.

Field

Specify a band field name to query. Get field names using the ENVINITF::GetBandFields method.

Keywords

BAND_INDEX

Set this keyword to an integer band index to specify which band segment to use to retrieve the value. The default is 0 which, if not set, defaults to the first band. Image segments usually contain one band segment per image band. See also the ENVINITF::GetBandValues method.

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.

Version History

ENVI 5.6.3

Introduced

API Version

4.2