1999.06.09 13:13 "RE: Large File Support", by Ed Grissom

I think anything we do is apt to be major. At least this would be an elegant way of handling the differences between old and new files and old and new programs / TIFF libraries. Eventually all (yes, *ALL*) programs would have to / should be changed to use the new layer. But at least this would eventually solve the problem.

What do you all think?

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.

Perhaps if everyone on the TIFF list sent email to Adobe, we would get some action...

P.S. -- Any bets as to when 64 bits will not be enough?

Even with the exponential growth we have seen in the last 10 years, I think that a number that is on the order of the number of atoms in Earth should be enough to get thru my lifetime :)

--
ed grissom
egrissom@ziimaging.com