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Re: layer stacking question [message #56566 is a reply to message #56563]

Sun, 28 October 2007 07:06

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

woopik@interia.pl writes:

> if i compare the pixel value (the same band)
> in the input and output file
>
> .tif -> layer stacking with idl all ok
> .tif -> layer stacking with envi GUI not ok

I think these confusing results can all be explained
by "ordering". IDL puts the (0,0) point at lower-left,
ENVI put it at upper left. When you write a TIF file
in IDL, if you don't reverse the Y values, the image
is almost always upside down, since TIFF seems to
use the same convention ENVI does. (And it doesn't
seem to matter HOW you set the ORDER keyword on
WRITE_TIFF.)

I think if you took your IDL layer and did this:

layer = Reverse(layer,2)

things will make more sense to you.

Cheers,

David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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[Message index]

		Re: layer stacking question By: woopik on Tue, 30 October 2007 02:42
		Re: layer stacking question By: Tal on Tue, 30 October 2007 02:21
		Re: layer stacking question By: woopik on Mon, 29 October 2007 02:14
		Re: layer stacking question By: David Fanning on Sun, 28 October 2007 07:06
		Re: layer stacking question By: woopik on Sun, 28 October 2007 05:07

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