Return-Path: <tiff-bounces@remotesensing.org>
Received: from xserve.flids.com (adsl-065-083-169-202.sip.mco.bellsouth.net [65.83.169.202])
        by inmx010.isp.belgacom.be (8.12.11/8.12.11/Skynet-IN-2.32) with ESMTP id j42Io0s9015788
        for <joris.at.lebbeke@skynet.be>; Mon, 2 May 2005 20:50:01 +0200
        (envelope-from <tiff-bounces@remotesensing.org>)
Received: from adsl-065-083-169-202.sip.mco.bellsouth.net (localhost [127.0.0.1])
	by xserve.flids.com (Postfix) with ESMTP
	id 8970824EC604; Mon,  2 May 2005 14:48:07 -0400 (EDT)
X-Original-To: tiff@remotesensing.org
Delivered-To: tiff@remotesensing.org
Received: from scooby.simplesystems.org (scooby.simplesystems.org
	[65.66.246.67])
	by xserve.flids.com (Postfix) with ESMTP id 03E2924EC5DE
	for <tiff@remotesensing.org>; Mon,  2 May 2005 14:48:03 -0400 (EDT)
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
	j42Im1Ai020501; Mon, 2 May 2005 13:48:01 -0500 (CDT)
Date: Mon, 2 May 2005 13:48:01 -0500 (CDT)
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] Color TIFF/JPEG compression questions
In-Reply-To: <002001c54f46$d8920380$48a6f651@dfgrrxsknr4e>
Message-ID: <Pine.SOC.4.60.0505021344480.24410@blade.simplesystems.org>
References: <741E24F735AED141B61948AC155E7DAA0E6148@CORPDALLMSG05.na.srcp.net>
	<002001c54f46$d8920380$48a6f651@dfgrrxsknr4e>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
Cc: "Frank, Jason" <JasonFrank@srcp.com>, tiff@remotesensing.org
X-BeenThere: tiff@remotesensing.org
X-Mailman-Version: 2.1.2
Precedence: list
List-Id: TIFF and libtiff discussion  <tiff.remotesensing.org>
List-Unsubscribe: <http://xserve.flids.com/mailman/listinfo/tiff>,
	<mailto:tiff-request@remotesensing.org?subject=unsubscribe>
List-Archive: <http://xserve.flids.com/pipermail/tiff>
List-Post: <mailto:tiff@remotesensing.org>
List-Help: <mailto:tiff-request@remotesensing.org?subject=help>
List-Subscribe: <http://xserve.flids.com/mailman/listinfo/tiff>,
	<mailto:tiff-request@remotesensing.org?subject=subscribe>
Sender: tiff-bounces@remotesensing.org
Errors-To: tiff-bounces@remotesensing.org
X-UIDL: 000000000023ceae.0000019a
X-MSP-STORE: Mon, 02 May 2005 20:50:10 +0200
Status:   

On Mon, 2 May 2005, Joris wrote:
>
>> So, I think that tiffinfo might be playing correctly here (since it
>> agrees with tiffdump, and I don't see any obvious problems with the
>> code.)
>
> We should check that we are talking about the exact same quad-jpeg.tif. I know
> for a fact that AsTiffTagViewer shows exactly what is there, and, unlike
> LibTiff, that stuff isn't burdoned with an actual image decoder part and a
> subsampling-fixup scheme and such... So if AsTiffTagViewer doesn't mention the
> tag, and tiffinfo does, I know for a fact that tiffinfo must be wrong.

Tiffinfo seems to dump information the way libtiff would handle it 
(e.g. includes some defaults).  Tiffdump should be used to produce a 
raw dump of TIFF information.

> A newer version of AsTiffTagViewer that isn't published yet, also supports hex
> viewing of just about any structure in a TIFF file. With this version I was able
> to triple-check, and sure enough, the tag count of this IFD shows as 14 in a hex
> dump that is merely a hex dump and cannot possibly be wrong. 14 is the number of
> tags shown by both versions of AsTiffTagViewer. So tiffinfo *does* add the
> default or fixed-up or whatever values of YCbCrSubsampling even though the tag
> is *not* there.

I am still eagerly awaiting the release of this software. :-)

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