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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 14:08 "Re: Large File Support", by Ed Grissom

In a previous message, Frank said:


> 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. 
> 
> 
As far as I can tell, here are the necessary changes:

++++++++++++++++start of changes++++++++++++++++++++++

Initial file bytes changes:
==========================

- TIFF magic number changes from "42" to "84" (double 42 ??)
- Initial IFD offset is 8 bytes instead of 4
- Next IFD offset at the end of a block of tags will have to be 8-bytes
instead of 4. 


New Data Type definitions:
==========================

LONG64  - A 64 bit unsigned integer
SLONG64 - A 64 bit signed integer"


Tag Definition:
===============

A tag is now made up of 16 bytes,  the last field is 8 bytes long, and
either contains the data (if it will fit in 8 bytes), or an 8 byte pointer
to the location of the data.


Redefinition of Existing Tags:
==============================

All tags that currently require a 4 byte pointer to data will use an 8 byte
pointer in the new format.

++++++++++++++end of changes++++++++++++++++++++++++

The data offset tags (stripoffsets, tileoffsets) will _have_ to contain
8-byte pointers.  Other TAGs that use offsets ( resolution, bits/sample/band
) will almost certainly have to use 8-byte pointers also, since we cannot
guarantee the location that this data will be stored at.  

I don't see how we can put an 8-byte pointer in _some_ TAGs without changing
the size of all TAGs.  Since we are redefining the size of a TAG structure,
I would not say that the changes are modest.  


As far as contacting Adobe, I tried a variety of email addresses, but the
only one that responded was the "mail customer support" link on the
www.adobe.com web site.  I don't think it was on the main page, but
somewhere under customer support.

Unfortunately, the response I got was a canned message to call the 1-800
number.

--
ed grissom
egrissom@ziimaging.com