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To: Sven Devriese <sdevries@eps.agfa.be>
cc: tiff@sgi.com
Subject: Re: BITSPERSAMPLE question 
In-reply-to: Your message of Thu, 09 Jan 1997 13:28:04 +0100 
             <32D4E454.4A11@eps.agfa.be> 
Date: Thu, 09 Jan 1997 11:23:28 -0500
Message-ID: <19687.852827008@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
Sender: owner-tiff@relay.engr.SGI.COM
Precedence: bulk

> From what I understand of the TIFF 6.0 spec (pg. 28-29),
> a TIFF implementation should be able to cope with
> different bit depths for every channel.

The spec allows such images to be represented, but it does not
require TIFF readers to handle them.  (Note that all flavors of
baseline TIFF have equal bitspersample for each channel.)
This is one of many optional features of TIFF.

> After looking
> at the sources, I think that libtiff doesn't allow this.

Correct, libtiff is not designed to support this.  AFAIK,
Sam has no plans to improve libtiff in that particular direction.
Such images are very few and far between.

			regards, tom lane
