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June 1999

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1999.06.03 19:48 "Large File Support", by Bruce Forsberg
1999.06.04 03:45 "Re: Large File Support", by Frank Warmerdam
1999.06.04 07:32 "Re: Large File Support", by Rob Tillaart
1999.06.07 07:05 "Re: Large File Support", by Rainer Wiesenfarth
1999.06.08 21:14 "Re: Large File Support", by Peter Smith
1999.06.08 21:58 "Re: Large File Support", by Ed Grissom
1999.06.08 22:52 "Re: Large File Support", by Peter Smith
1999.06.09 01:27 "Re: Large File Support", by Martin Bailey
1999.06.09 06:50 "Re: Large File Support", by Owen Pearn
1999.06.09 14:33 "Re: Large File Support", by Martin Bailey
1999.06.09 08:07 "Re: Large File Support", by Rob Tillaart
1999.06.04 18:35 "Re: Large File Support", by Bruce Forsberg
1999.06.07 13:03 "Re: Large File Support", by Frank Warmerdam
1999.06.09 03:05 "Re: Large File Support", by <glen@lumisys.com>
1999.06.09 13:13 "Re: Large File Support", by Ed Grissom
1999.06.09 13:33 "Re: Large File Support", by Frank Warmerdam
1999.06.09 14:08 "Re: Large File Support", by Ed Grissom
1999.06.09 18:50 "Re: Large File Support", by Chris Barker
1999.06.09 18:41 "Large File Support", by Chris Barker
1999.06.10 13:21 "Re: Large File Support", by Chris Hanson
1999.06.10 13:52 "Re: Large File Support", by Frank Warmerdam
1999.06.10 14:37 "Re: Large File Support", by John Aldridge
1999.06.10 15:10 "Re: Large File Support", by Peter Smith
1999.06.10 16:56 "Re: Large File Support", by Chris Barker
1999.06.14 11:16 "Re: Large File Support", by Martin Bailey
1999.06.14 14:58 "Re: Large File Support", by Tom Lane
1999.06.14 15:30 "Re: Large File Support", by Eric Shapiro
1999.06.14 16:27 "Re: Large File Support", by Chris Barker
1999.06.14 15:51 "Re: Large File Support", by Martin Bailey
1999.06.09 15:52 "Re: Large File Support", by Ed Grissom
1999.06.10 09:48 "Re: Large File Support", by Klaus Bartz
1999.06.10 13:05 "Re: Large File Support", by Chris Hanson
1999.06.11 01:48 "Re: Large File Support", by <glen@lumisys.com>

1999.06.09 18:50 "Re: Large File Support", by Chris Barker

Frank Warmerdam wrote:
> 
> "Grissom, Ed" wrote:
> > Glen, I think your idea has merit, and something like this would probably be
> > the right way to go for any TIFF library.
> >
> > However, we first need a specification that describes the details of the new
> > format.   This new format would _have_ to have the "magic" number changed
> > since the initial IFD offset will be 8 bytes instead of 4.  If we don't
> > change the magic we will break all existing TIFF readers.
> >
> > Could we call this TIFF ? I believe that Adobe has the name trademarked or
> > copyrighted (whichever is appropriate).  Could we use all the ideas in TIFF
> > (tags, tag names, etc..) without Adobe's blessing ?  At the start of the
> > TIFF 6.0 document there is some info on how to request changes to TIFF, but
> > I have had no success trying to get Adobe to pay attention to me.
> 
> Folks,
> 
> If we change the format enough that the existing libraries cannot be easily
> adapted to supporting the old, and new formats I think we should ask ourselves
> whether the world needs yet another image format.

It seems to me you have not been paying attention. The world
*definitely* needs
another file format that can support files larger than 4Gb, as evidenced
by all
this email! What we don't need is another proprietary format.

> 
> Assuming that we could get away with calling it TIFF64, and that libtiff
> could be adapted to supporting the old and new format I think it would be
> world pursing a 64bit version of the format.

I would not suggest keeping libtiff as it is. We need public domain code
along
with a public domain format, but what we *really* need is a standard
interface
spec for the parse/write library to go with the file format. This way we
can
have public and proprietary implementations that are interchangeable...

> 
> I would hope we could do this in a way that other TIFF reading libraries
> could be fairly easily adapted to also support the TIFF64 standard.  I think
> this should be one of our objectives.  Of course, keeping essentially the same
> model with modest changes in the format to support larger numbers should go
> a long way to satisfying that objective.

Since we have to change, I believe we should change to improve where
possible;
but I think TIFF64 (or whatever) should be simpler if possible. The TIFF
model
has much which is good, but there are way too many possible variations
that are
not specified. That should be fixed.

> 
> Best regards,
> 
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turned up | Frank Warmerdam, warmerda@home.com
> light and sound - activate the windows | http://members.home.com/warmerda
> and watch the world go round - Rush    | Geospatial Programmer for Rent

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