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From: Andrey Kiselev <dron@ak4719.spb.edu>
Date: Tue, 7 Jun 2005 23:15:53 +0400
To: tiff@remotesensing.org
Subject: Re: [Tiff] Group4 compression & alpha channel
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Status:   

Hi, Bob,

On Tue, Jun 07, 2005 at 01:43:29PM -0500, Bob Friesenhahn wrote:
> It has been observed that when GraphicsMagick writes a min-is-black 
> TIFF image with Group4 compression and an alpha channel (as an extra 
> sample) that the right half of the image is lost.  The image 
> description is:
...
> I strongly suspect that this loss of data is due to libtiff but have 
> not done a thorough investigation yet to make absolutely sure.  The 
> same occurs when using FAX compression.
> 
> By simply not requesting Group4 or FAX compression, the file is saved 
> and read ok.  This works:
...
> Are there any known issues in libtiff with this scenario?

I do not remember any reports of such a bug. I think it is a matter for
our Bugzilla.

Regards,
Andrey


-- 
Andrey V. Kiselev
Home phone:  +7 812 5970603  ICQ# 26871517
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