Return-Path: owner-tiff@olympiakos.com
Return-Path: <owner-tiff@olympiakos.com>
Received: from localhost (localhost [127.0.0.1])
	by at1895.spb.edu (8.9.3/8.9.3) with ESMTP id SAA01018
	for <dron@localhost>; Sat, 24 Mar 2001 18:31:10 +0300
Received: from eudoramail.com [209.185.123.45]
	by localhost with POP3 (fetchmail-5.6.0)
	for dron@localhost (single-drop); Sat, 24 Mar 2001 18:31:10 +0300 (MSK)
Received: from gate7.olympiakos.com ([207.176.88.85]) by shared1-mail.whowhere.com; Fri Mar 23 21:44:41 2001
Received: from localhost (daemon@localhost)
	by gate7.olympiakos.com (8.9.3/8.9.3) with SMTP id MAA25828;
	Wed, 21 Mar 2001 12:41:45 -0500
Received: by gate7.olympiakos.com (bulk_mailer v1.9); Wed, 21 Mar 2001 12:39:48 -0500
Received: (from majordom@localhost)
	by gate7.olympiakos.com (8.9.3/8.9.3) id MAA25443
	for tiff-outgoing; Wed, 21 Mar 2001 12:39:48 -0500
X-Authentication-Warning: gate7.olympiakos.com: majordom set sender to owner-tiff@olympiakos.com using -f
Received: from mta06-svc.ntlworld.com (mta06-svc.ntlworld.com [62.253.162.46])
	by gate7.olympiakos.com (8.9.3/8.9.3) with ESMTP id MAA25432
	for <tiff@olympiakos.com>; Wed, 21 Mar 2001 12:39:43 -0500
Received: from ntlworld.com ([62.255.96.214]) by mta06-svc.ntlworld.com
          (InterMail vM.4.01.02.27 201-229-119-110) with ESMTP
          id <20010321173935.RXVL285.mta06-svc.ntlworld.com@ntlworld.com>
          for <tiff@olympiakos.com>; Wed, 21 Mar 2001 17:39:35 +0000
Message-ID: <VvYKDrD+XOu6Ewgi@ntlworld.com>
Date: Wed, 21 Mar 2001 17:33:50 +0000
To: tiff@olympiakos.com
From: Neil Durant <neil@sphere3.demon.co.uk>
Subject: Re: Wang tiff
References: <OF0FF71259.38B2DB3B-ON87256A16.005E366D@LocalDomain>
In-Reply-To: <OF0FF71259.38B2DB3B-ON87256A16.005E366D@LocalDomain>
MIME-Version: 1.0
Content-Type: text/plain;charset=us-ascii;format=flowed
User-Agent: Turnpike/6.00-Beta-2-U (<W4VFAtGCNAW4to49ltN770$Brj>)
Sender: owner-tiff@olympiakos.com
Status: RO
Content-Length: 1621
Lines: 35

Nenad Rijavec <nenad@us.ibm.com> writes
>I looked at the sample file. This is a single-page Wang TIFF, which means
>that it can be treated as a TIFF file with an unknown tag. Wang private
>tag, 0x80a6, contains an offset to the page control structure. In your
>file, this value is 0, which means the page contains a single page only. I
>should note, though, that the Wang files I've seen so far use 0x80a7 tag,
>so I am conjecturing a bit.
>
>I think the problem you face is not Wang format, but rather your JPEG
>compression. The file uses the old-style compression 6 (JPEG). And uses it
>with vengeance - the Huffman and quantization tables are scattered
>throughout, and each block row is compressed in a separate strip. It's well
>known that this type of compression is ill-defined and should not be used,
>which is why you are having trouble finding the readers for your file.
>
>Assuming all your files have the same format, you might use the data in
>your file to reassemble a proper JFIF file without actually decompressing
>your bitmap.

Hmmm.  From what everyone is saying it looks like I'm going to have to 
do a bit of a reverse-engineering job, and cut the file up and 
reassemble it.

Does anyone have any URLs etc for where I can find some specifications 
on the TIFF file format, and how extensions such as these Wang ones are 
integrated into the format?

Thanks for your help!

Neil
-- 
===================================================================
Neil Durant
<neil@sphere3.demon.co.uk>                        Fax: 08700 520159
===================================================================

