ENVINITF::GetSegmentValue

The GetSegmentValue method retrieves the values of selected fields from NITF or MIE4NITF 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 NROWS field

Print, NITF.GetSegmentValue('image', 1, 'NROWS')

Result:

Syntax

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

Return Value

This method returns the value of a segment field.

Arguments

Type

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

DES

Header

Image

Text

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 field name to query. Get field names using the ENVINITF::GetSegmentFields method.

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.

Version History

ENVI 5.6.1

Introduced