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Message-ID: <005401c85425$491ed660$7b89c554@katjad31f0d374>
From: "Joris Van Damme \(AWare Systems\)" <joris.at.lebbeke@skynet.be>
To: "Frank Warmerdam" <warmerdam@pobox.com>,
        "Nikhil Shirahatti" <shirahatti@gmail.com>
References: <fb91ffe0801101103o3addbc5bhd6fb7234fbef1216@mail.gmail.com><Pine.SOC.4.64.0801101531190.2557@freddy.simplesystems.org><fb91ffe0801101340g1ea9c156h11b53e0d1aa7a03e@mail.gmail.com>
	<4786976C.7030502@pobox.com>
Subject: Re: [Tiff] LibTiff..Reading partial strips
Date: Fri, 11 Jan 2008 08:40:07 +0100
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Status:   

Frank,

Frank Warmerdam wrote:
> In addition to "strip chopping", libtiff also has the
> TIFFReadScanline() function for reading strips one scanline at a
> time.  This operates without needing to read and decompress the whole
> strip at once.

TIFFReadScanline and that sort of access might be more optimally streaming. 
But support for it depends on the particular subcodec, and I seem to 
remember not all subcodecs support it. It does not work on tiled images, 
either, and since there's no actual definition in the man pages of what 
should be returned on subsampled images, there's a bit of a mess in that 
case. So I essentially regard this scanline based access a broken concept in 
LibTiff.


Best regards,

Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
Download your free TIFF tag viewer for windows here:
http://www.awaresystems.be/imaging/tiff/astifftagviewer.html

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