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Message-ID: <3AF06364.5D3C@srz-berlin.de>
Date: Wed, 02 May 2001 21:43:32 +0200
From: Helge Blischke <H.Blischke@srz-berlin.de>
Organization: SRZ BERLIN
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To: "Michael O'Rourke" <morourke@Adobe.COM>
CC: tiff@olympiakos.com
Subject: Re: TIFFSetDirectory speed?
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Michael O'Rourke wrote:
> 
> How costly is it to set the directory in say a 5,000 page TIFF file? For
> instance, if I want to go to page 4,000 can libtiff easily jump there or
> does it actually have to read the previous 3,999 pages to get to page 4,000?
> 
> Michael

If I got the TIFF spec correctly, each page of a multipage TIFF file has
it's own
IFD, thus what you'd have to do is to walk through the IFD chain until
the page number
tag contains the desired page number.

As the spec allows the pages to be stored in any order, you may have to
inspect
more than your 3,000 IFDs.

Helge
-- 
H.Blischke@srz-berlin.de
H.Blischke@srz-berlin.com
H.Blischke@acm.org

