Message-ID: 3899ABA3.86A38B12@planetinternet.be
To: Andy <apex@calpha.com>, tiff@olympiakos.com
Subject: Re: Microsoft Imaging and Jpeg in TIFF
From: Joris Van Damme <as.van.damme.joris@planetinternet.be>
Date: Thu, 03 Feb 2000 17:24:03 +0100
Organization: AWare Systems
References: <FD7E8A8A5060D1119AEF0000F806A97F05EA9AD5@imps0024> <3898A337.FBBCAAB0@calpha.com> <3898DD0F.5A920F5C@planetinternet.be> <3898E285.84EF778D@calpha.com>
Sender: owner-tiff@olympiakos.com


Andy wrote:
> I use to make Wang JPEG images  the freely available "Wang Imaging for
> Windows 95." 

Yeah, I wasn't aware of it. Of course I have that fancy wang thing.
Thank you for pointing that out.

> Could you send me your sample TIFF/J image?  I would see how it is.  Thank
> you.

The only jpeg embedding tiff I've found is (or was?) part of the
official testpics collection, it is (or was) called quad-jpeg. It's a
good image, JPEG not OJPEG. I had some problems with it in the
beginning, but it turns out the libtiff/libjpeg combination is perfectly
able to read it *IF* you instruct libjpeg to ouput RGB instead of YCbCr
through the appropriate TIFF pseudo-tag. Otherwise, it gets as bad as an
access violation (but maybe I've made some bad changes or something, it
could be MY problem and not a libtiff/libjpeg problem).

Anyway, I'll mail it to your private account.

As for the problem here, OJPEG images that in fact are not OJPEG as they
should be... either we find a way to recognize them and decode them
(both!) with 100% certainty; or either we give up on OJPEG, that will
exclude these troublesome images too. At this point, I think I'll go for
that second option.



Joris



