Return-Path: <awaresystems.be+caf_=filtered=awaresystems.be@gmail.com>
Delivered-To: filtered@awaresystems.be
Received: from mx02.one.com (mx02.one.com [195.47.247.73])
	by mail6.local.one.com (Postfix) with ESMTP id 5F2BE300504C57
	for <filtered@awaresystems.be>; Sun, 21 Dec 2014 15:17:12 +0000 (UTC)
X-Virus-Scanned: by one.com
Received-SPF: pass (mx02: domain of awaresystems.be+caf_=filtered=awaresystems.be@gmail.com designates 209.85.217.180 as permitted sender)
X-Greylist: whitelisted by SQLgrey-1.8.0-rc2
Received: from mail-lb0-f180.google.com (mail-lb0-f180.google.com [209.85.217.180])
	by mx02.one.com (Postfix) with ESMTP id D7FF8A7619E
	for <filtered@awaresystems.be>; Sun, 21 Dec 2014 15:17:11 +0000 (UTC)
Received: by mail-lb0-f180.google.com with SMTP id l4so2815835lbv.25
        for <filtered@awaresystems.be>; Sun, 21 Dec 2014 07:17:11 -0800 (PST)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20130820;
        h=x-original-authentication-results:delivered-to:delivered-to:date
         :from:to:in-reply-to:message-id:references:user-agent:mime-version
         :cc:subject:precedence:list-id:list-unsubscribe:list-archive
         :list-post:list-help:list-subscribe:content-type
         :content-transfer-encoding:sender:errors-to;
        bh=JspvfgEsuo/T/8wdXK/IujTztHPkC/i+LWzOiUvGFCU=;
        b=OdGZbXDhQ0NGilMO1ApcCM5DQBjaT2CX9l6uy526KrtIyQYIjfJWEhweVzu9moPYB8
         gTZwdVh3jSjaCL9Sxutth1CA23xO7TfLgRCbBirtjORf4RCKN11PlRbRPEGpJ10AQS+M
         R+DSoXOMLg/EO5RmOP2cILUVh7dn7FgNZ8ecJFR8NwVnkQTCQchgh+vy5u8hM3EWwC2m
         H+qerEzDNMK3Us2+UCNB6PbsL4ttx413B2Hv01rT4X5LWcGeEFNPcOMw9+v+uQ8XOvIp
         6UML4wZVNkWQ3OHS+LcDrZYSMPBljxo+bRbIm5Z/tQpqWJbO7Cq3MBvVTp/MnoXAl/6M
         Yx7A==
X-Original-Authentication-Results: mx.google.com;       spf=none (google.com: tiff-bounces@lists.maptools.org does not designate permitted sender hosts) smtp.mail=tiff-bounces@lists.maptools.org
X-Received: by 10.152.5.198 with SMTP id u6mr17921332lau.42.1419175031463;
        Sun, 21 Dec 2014 07:17:11 -0800 (PST)
X-Forwarded-To: filtered@awaresystems.be
X-Forwarded-For: awaresystems.be@gmail.com filtered@awaresystems.be
Delivered-To: awaresystems.be@gmail.com
Received: by 10.114.181.147 with SMTP id dw19csp76273ldc;
        Sun, 21 Dec 2014 07:17:10 -0800 (PST)
X-Received: by 10.112.132.2 with SMTP id oq2mr17645959lbb.11.1419175028993;
        Sun, 21 Dec 2014 07:17:08 -0800 (PST)
Authentication-Results: mx.google.com;
       spf=none (google.com: tiff-bounces@lists.maptools.org does not designate permitted sender hosts) smtp.mail=tiff-bounces@lists.maptools.org
Received-SPF: none (google.com: tiff-bounces@lists.maptools.org does not designate permitted sender hosts) client-ip=195.47.247.73;
Received: by 10.112.74.9 with POP3 id p9mf4994299lbv.29;
        Sun, 21 Dec 2014 07:17:08 -0800 (PST)
X-Gmail-Fetch-Info: info@awaresystems.be 1 pop.awaresystems.be 110 info@awaresystems.be
Delivered-To: info@awaresystems.be
Received: from mx02.one.com (mx02.one.com [195.47.247.73])
	by mail6.local.one.com (Postfix) with ESMTP id 8AB4A300A3B035
	for <info@awaresystems.be>; Sun, 21 Dec 2014 15:10:51 +0000 (UTC)
X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0-rc2
Received: from lists.maptools.org (ks365428.kimsufi.com [94.23.4.142])
	by mx02.one.com (Postfix) with ESMTP id 60491A75607
	for <info@awaresystems.be>; Sun, 21 Dec 2014 15:10:51 +0000 (UTC)
Received: from [10.1.0.241] (localhost.localdomain [127.0.0.1])
	by lists.maptools.org (Postfix) with ESMTP id 163E535C034;
	Sun, 21 Dec 2014 10:10:03 -0500 (EST)
Received: from blade.simplesystems.org (blade.simplesystems.org [65.66.246.74])
	by lists.maptools.org (Postfix) with ESMTPS id 0F95435C02D
	for <tiff@lists.maptools.org>; Sun, 21 Dec 2014 10:08:01 -0500 (EST)
Received: from freddy.simplesystems.org (freddy.simplesystems.org
	[65.66.246.65])
	by blade.simplesystems.org (8.14.4+Sun/8.14.4) with ESMTP id
	sBLF87eW012516; Sun, 21 Dec 2014 09:08:07 -0600 (CST)
Date: Sun, 21 Dec 2014 09:08:07 -0600 (CST)
From: Bob Friesenhahn <bfriesen@simple.dallas.tx.us>
X-X-Sender: bfriesen@freddy.simplesystems.org
To: Tom Lane <tgl@sss.pgh.pa.us>
In-Reply-To: <14803.1419128656@sss.pgh.pa.us>
Message-ID: <alpine.GSO.2.01.1412210900330.18732@freddy.simplesystems.org>
References: <201412151849.41073.even.rouault@spatialys.com>
	<alpine.GSO.2.01.1412201642240.18732@freddy.simplesystems.org>
	<201412210006.13468.even.rouault@spatialys.com>
	<alpine.GSO.2.01.1412201823330.18732@freddy.simplesystems.org>
	<14803.1419128656@sss.pgh.pa.us>
User-Agent: Alpine 2.01 (GSO 1266 2009-07-14)
MIME-Version: 1.0
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.2
	(blade.simplesystems.org [65.66.246.90]);
	Sun, 21 Dec 2014 09:08:08 -0600 (CST)
Cc: TIFF <tiff@lists.maptools.org>
Subject: Re: [Tiff] Unnecessary bigger JPEG-compressed TIFF
X-BeenThere: tiff@lists.maptools.org
X-Mailman-Version: 2.1.9
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>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: tiff-bounces@lists.maptools.org
Errors-To: tiff-bounces@lists.maptools.org

On Sat, 20 Dec 2014, Tom Lane wrote:

> Bob Friesenhahn <bfriesen@simple.dallas.tx.us> writes:
>> On Sun, 21 Dec 2014, Even Rouault wrote:
>>> And from my testing with old imagemagick it seems that gm convert
>>> doesn't produce a YCbCr JPEG-compressed TIFF.
>
>> Hmmm ...
>> Does YCbCr make that big of a difference?
>
> Possibly.  What were you doing instead?  RGB output would be substantially
> larger than YCbCr, possibly approaching 3x larger.  (That still isn't
> enough to explain the reported size difference though.)

GraphicsMagick is setting the photometric to PHOTOMETRIC_RGB and 
setting the TIFF TIFFTAG_JPEGCOLORMODE tag to JPEGCOLORMODE_RGB.  I 
was hoping to avoid having to deal with YCbCr directly and that the 
RGB would be magically transformed to YCbCr (by libjpeg) but it seems 
that is not what is happening.  RGB is being stored instead.

GraphicsMagick should of course be able to directly input/output YCbCr 
data in TIFF, but supporting the various sampling modes seem like a 
chore. To be honest, I have not researched it at all.

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/
