Return-Path: <tiff-bounces@lists.maptools.org>
Received: from inas017.isp.belgacom.be (localhost [127.0.0.1])
        by inav030.isp.belgacom.be (8.12.11/8.12.11/Skynet-IN-AV-3.00) with ESMTP id jA7KZu68020976
        for <joris.at.lebbeke@skynet.be>; Mon, 7 Nov 2005 21:35:56 +0100
        (envelope-from <tiff-bounces@lists.maptools.org>)
Received: from inmx019.isp.belgacom.be (inmx019.isp.belgacom.be [195.238.5.138])
        by inas017.isp.belgacom.be (8.12.11/8.12.11/Skynet-IN-AS-2.03) with ESMTP id jA7KZmDl002527
        for <joris.at.lebbeke@skynet.be>; Mon, 7 Nov 2005 21:35:51 +0100
        (envelope-from <tiff-bounces@lists.maptools.org>)
Received: from duke.maptools.org (r153.dmsolutions.ca [209.217.116.153] (may be forged))
        by inmx019.isp.belgacom.be (8.12.11/8.12.11/Skynet-IN-2.32) with ESMTP id jA7KZhcU004010
        for <joris.at.lebbeke@skynet.be>; Mon, 7 Nov 2005 21:35:44 +0100
        (envelope-from <tiff-bounces@lists.maptools.org>)
Received: from duke.maptools.org (duke.maptools.org [127.0.0.1])
	by duke.maptools.org (8.12.11/8.12.10) with ESMTP id jA7KVIdC028429;
	Mon, 7 Nov 2005 15:31:24 -0500
Received: from scooby.simplesystems.org (scooby.simplesystems.org
	[65.66.246.67])
	by duke.maptools.org (8.12.11/8.12.10) with ESMTP id jA7KVFNi028426
	for <tiff@lists.maptools.org>; Mon, 7 Nov 2005 15:31:15 -0500
Received: from blade.simplesystems.org (blade.simplesystems.org [65.66.246.74])
	by scooby.simplesystems.org (8.12.10+Sun/8.12.10) with ESMTP id
	jA7KV1us004119; Mon, 7 Nov 2005 14:31:01 -0600 (CST)
Date: Mon, 7 Nov 2005 14:31:01 -0600 (CST)
From: Bob Friesenhahn <bfriesen@simple.dallas.tx.us>
X-X-Sender: bfriesen@blade.simplesystems.org
To: Joris <joris.at.lebbeke@skynet.be>
Subject: Re: [Tiff] Writing bilevel and transparent TIFFs efficiently
In-Reply-To: <001c01c5e3d0$05d4c4e0$4dc2f451@dfgrrxsknr4e>
Message-ID: <Pine.SOC.4.60.0511071427340.7597@blade.simplesystems.org>
References: <7157931292F8D64D9747FBE4640C992F01C31FC5@redbaron.int.infograph.com>
	<Pine.SOC.4.60.0511030930230.7597@blade.simplesystems.org>
	<001c01c5e3d0$05d4c4e0$4dc2f451@dfgrrxsknr4e>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
Cc: Tiff List <tiff@lists.maptools.org>, Rupali Holmes <rupalih@infograph.com>
X-BeenThere: tiff@lists.maptools.org
X-Mailman-Version: 2.1.4
Precedence: list
List-Id: TIFF and libtiff discussion <tiff.lists.maptools.org>
List-Unsubscribe: <http://lists.maptools.org/mailman/listinfo/tiff>,
	<mailto:tiff-request@lists.maptools.org?subject=unsubscribe>
List-Archive: <http://lists.maptools.org/mailman/private/tiff>
List-Post: <mailto:tiff@lists.maptools.org>
List-Help: <mailto:tiff-request@lists.maptools.org?subject=help>
List-Subscribe: <http://lists.maptools.org/mailman/listinfo/tiff>,
	<mailto:tiff-request@lists.maptools.org?subject=subscribe>
Sender: tiff-bounces@lists.maptools.org
Errors-To: tiff-bounces@lists.maptools.org
X-UIDL: 000000000023ceae.00000e03
X-MSP-STORE: Mon, 07 Nov 2005 21:36:02 +0100
Status:   

On Mon, 7 Nov 2005, Joris wrote:
>
>> It is possible to use an associated alpha channel with palette
>> (PHOTOMETRIC_PALETTE) images,
>
> Is it? I'm not entirely convinced.

I did not see anything in the specification which specifically forbids 
it.  However, it is much easer to read such files than to write them 
since writing them requires computing a palette which is conjoined 
with the alpha channel.  A very ugly thing indeed.

Bob
======================================
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
_______________________________________________
Tiff mailing list: Tiff@lists.maptools.org
http://lists.maptools.org/mailman/listinfo/tiff
http://www.remotesensing.org/libtiff/
