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Date: Wed, 22 Aug 2007 10:36:49 +0100
From: jcupitt@gmail.com
To: "Oliver Geisen" <oliver.geisen@kreisbote.de>
Subject: Re: [Tiff] How to handle big single-strip images?
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On 8/22/07, Oliver Geisen <oliver.geisen@kreisbote.de> wrote:
> i wonder what will happen if one opens an tiff image where all the
> data is in a SINGLE strip (some writers offer this option) and also
> compressed (G4) and someone tries to use TIFFReadScanline with it?
> I would expect that libtiff needs to read the whole strip, because
> it's compressed, into memory. Or is it possible to read compressed
> data by chunks?

This is what the tiled mode is for. Strip TIFFs (as you say) are not
very suitable for random access. Tiled TIFFs work well with random
access, even with compression.

We use JPEG-compressed tiled TIFF pyramids in our web image viewer and
performance is good. There's a demo with a 80,000 by 40,000 pixel
image here:

http://iipimage.sourceforge.net/demo.shtml

John
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