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

2021.09.29 16:33 "Re: [Tiff] [GeoTIFF.swg] Proposal to create a OGC BigTIFF standard", by Emmanuel Devys

“Perhaps the relevant issue to solve is: who is responsible for BigTIFF? I have no satisfactory answer for this.”

I guess there is no satisfactory answer for this as you say, in the sense of no authority. For sure, the community that was behind the BigTIFF specification, as well as the developers of the libtiff who extend it for support of BigTIFF, maintained under the OSGeo, as well as the community behind bigtiff.org<http://bigtiff.org> share some responsibility.

If the ownership of TIFF is clear (Adobe), it is also clear that Adobe claim no interest in BigTIFF. This has been confirmed by some investigation and email-exchange with OGC.

The registration of TIFF tags for domain-specific metadata is another topic, and as you know, there is no transparency in the documentation of the “public” TIFF private tags offered by Adobe. Fortunately, Aware systems provides some documentation at https://www.awaresystems.be/imaging/tiff/tifftags.html (but this is another topic than BigTIFF).

Another relevant issue to solve is how to sustain BigTIFF (and its aim for “64-bit” ness), as it is obvious there are interests for it, in the medical, geospatial and for sure other domains.

Given this context, IMHO the proposal by OGC to openly make available and maintain the BigTIFF (limited to its core aspects as shown under bigtiff.org – the “64-bit” ness) appears as an acceptable solution, with an open standardisation organization providing its standards for free, as well as structure / tools for documenting, testing and maintaining the standards. To my knowledge, it is the only one emerging right now,. If there would be other alternatives for going forward for a sustainable bigTIFF, I’d be happy to get information on alternatives (but no echo on my radar).

I would appreciate if some consensus could be reached on trying to move forward on this bigTIFF action. And if there are solid objections or alternate proposals for reaching the goal of a sustained bigTIFF, to have them submitted and documented sufficiently in order to consider.

Emmanuel Devys
IGN - Standardization Project Manager – Geography, Forests & Environment
(previously chair of OGC GeoTIFF.SWG)

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