2017.12.21 14:14 "[Tiff] Pull request to add ZStandard/ZSTD codec", by Even Rouault

2018.02.18 13:36 "Re: [Tiff] Pull request to add ZStandard/ZSTD codec", by Kemp Watson

The previous system required no review to request or allocate private tags. Re new tags or compression schemes, including ZSTD, do note that the resultant files may NOT have a .tif or .tiff file extension, as the codec is not part of Baseline TIFF 6.0.

One of the issues, however, with that open approach, is the duplication of codec tags. There are at least three now for JPEG 2000; I registered PNG and JPEG XR some years agoŠ by necessity in the private tag area, as there was no one to talk to about official adoption, Adobe did not respond to my enquiries. How does anybody find those right now, and how messed do things get once more are registered for the same purpose, and implementations have to handle all of them?

This boils down to truly private vs official tags, but the current spec locks the official tags down tight for the sake of compatibility (not necessarily a bad thing, but it¹s a long time ago now). And no one seems to be able to track down the keeper of the spec, let alone discuss revisions. As per my previous post (which I did not see make it to the group): The TIFF standard is now getting a bit of gray around the chin, and there appears to be both no sponsor interest, and no technical mechanism, of carefully managing the process of keeping the standard in step with current codecs, and current development practice.

Will TIFF acknowledge itself as a legacy file format, will it undertake to bring itself current in a managed fashion, or will it descend into chaos as implementors chaotically add their own tags and extensions? Could we get clarification from Adobe on their intent? - at the moment, all things point to abandonment.

W. Kemp Watson


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On 2018-02-16, 7:00 AM, "tiff-bounces@lists.maptools.org on behalf of rleigh@codelibre.net" <tiff-bounces@lists.maptools.org on behalf of

rleigh@codelibre.net> wrote:

On 2018-02-15 13:59, Leonard Rosenthol wrote:

>> Sorry about this folks ­ the person who is now managing the TIFF >> work has been otherwise occupied and I haven¹t been able to push

>> this throughŠ

>> I agree that we should probably come up with a better model ­ but I >> don't see new things being registered all that often so it¹s hard.

Dear Leonard,

Could I make a suggestion for something which might help? Have Adobe considered moving the tag registry into public source control such as github.com/adobe/tiff-tag-registry? This would allow for a pull request-based approach to propose and review new tags. You could even use github pages to automatically publish the tag registry documentation after merging. This would make the process more open and transparent, and might reduce the amount resources which Adobe requires for ongoing maintenance.

While the tag registry is the most immediate concern, have you considered a similar approach for the TIFF specification itself?

If the existing Adobe github repository isn't suitable, the libtiff gitlab organisation could potentially be used to host additional repositories.

Kind regards,