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Date: Thu, 3 Nov 2005 12:06:35 -0500
From: Frank Warmerdam <warmerdam@pobox.com>
To: Bob Friesenhahn <bfriesen@simple.dallas.tx.us>
Subject: Re: [Tiff] Writing bilevel and transparent TIFFs efficiently
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Cc: tiff@lists.maptools.org, Rupali Holmes <rupalih@infograph.com>
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Status:   

On 11/3/05, Bob Friesenhahn <bfriesen@simple.dallas.tx.us> wrote:
> Ultimately, the PHOTOMETRIC_RGB photometric with associated alpha at 8
> bits per sample is the best supported by readers even though it is not
> very efficient.

Bob / Rupali,

It seems to me that with a suitable compression format
(Deflate or LZW) the RGBA data form should compress very
well if there are only two 32bit values ever used.

As Bob notes this would likely be the most portable way of
transporting a color image with transparency.

Best regards,
--
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam@pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent

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