2021.09.28 13:49 "[Tiff] Proposal to create a OGC BigTIFF standard", by Even Rouault

2021.09.28 15:08 "Re: [Tiff] Proposal to create a OGC BigTIFF standard", by Kemp Watson

Hi Even et al:

To my knowledge, the community that was behind the BigTIFF specification is now effectively Leica (medical, not Geosystems).

The initial specification came from Ole Eichhorn, then at Aperio, a digital pathology company which was acquired by Leica.

The involvement of Aware systems as far as I know was only hosting a discussion on their mailing list, and documenting essentially a copy of Ole's work. I don't believe the participants were from Aware. Anyone do please correct me if my understanding is incomplete or incorrect.

However, this unofficial specification only covers a migration of TIFF to 64-bits, and says nothing in particular about tiling, multi-resolutions, multi-channels, bit depths, compression, TIFFtags/metadata, etc, all of which need to be defined per application at a higher level. Various stabs at this for multiresolution imaging have been made over the years: Aperio.svs, COG, ZIF (my own), OME-TIFF (used ZIF as a reference point), and many 99% similar flavors of pyramidal tiled (big)TIFF. Shame we can't all get it together.

Given that GeoTIFF and COG specifications exist, what is OGC intending to add beyond that? Is it just the "64-bit"ness, or metadata?

There is no formal maintainer; the AWARE systems site does not maintain the BigTIFF specification, that is just a reference; another is at http://bigtiff.org, a site now owned by Leica.

And I'm not sure the wording on https://github.com/opengeospatial/BigTIFF is as intended?: "it becomes an OGC standard" sounds like OGC intends to take over ownership of BigTIFF? Leica might have something to say about that, although the specification has been put in the public domain. Personally, I really wish Adobe as the owner of the TIFF specification would step up to the plate with this, and update the actual TIFF specification to cover BigTIFF. Their focus has been elsewhere for many years, but this would be a great community service.


Kemp Watson
Objective Pathology Services
Toronto, Canada