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Libtiff goes offline

madfileformatscience.garymcgath.com

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Re: Libtiff goes offline

#101

Post by cyphar »

Someone wrote: post #80
cyphar wrote: post #62

Earlier quoted context omitted.

If you have a maintainer who signs their commits, you trust their signatures and call it a day. Go with the latest commit and that tells you the history that they have cryptographically claimed is "correct".

One problem I see there is that, with git, you still have to take care that you keep around all the commits that at any given point in time were declared "correct". For example, if a commit is amended and force pushed out to remove a backdoor from a popular package, a site interested in the history of the library will want to ensure that the faulty commit stays around. I'm not even sure that is 100% possible, but it,…

You never rewrite published history with git. It's fine to force push signed git commits to a random branch that are going to be rewritten -- that's just how development works. But when you merge something, it stays that way. Touching history in release branches is something that will always end in tears (all of the tagging breaks, everyone's clone will complain when they update it, etc). Just bad news all around.

As for a site which cares about archiving, they can almost certainly add a tag for every commit they slurp up (making sure it doesn't get hit by the git gc). Though, I'm fairly sure that you can just configure your git instance to never garbage collect.

Re: Libtiff goes offline

#104

Post by rwmj »

banachtarski wrote: post #7

Tiff? That is a format I haven't heard in a long time. edit: to everyone replying. TIFF is awful. We have lossless compression now (read PNG) which is at least a billion times better. We shouldn't use it for anything in this day and age. Hell, just DEFLATE your TIFF and call it a new format. It will be better than TIFF

TIFF was used (probably still is) to store data from gas detectors. It wasn't called TIFF, but it was based on the format plus custom tags to store extra data and image layers. As a format it is super-flexible.

Re: Libtiff goes offline

#105

Post by gpvos »

sspiff wrote: post #102
japaget wrote: post #3

The code is now being hosted at http://www.simplesystems.org/libtiff/ with a mirror site at http://libtiff.maptools.org/ .

Or at http://libtiff.org/

NO. That is an old, hijacked domain. Read the story on Wikipedia: https://en.wikipedia.org/wiki/LibTIFF .

Re: Libtiff goes offline

#106

Post by gpvos »

ashitlerferad wrote: post #68
dustinmr wrote: post #37

Seems like we've had organizations that house ideas for the public good for centuries now. Why not involve libraries in the effort? They could keep a "master" copy and github.com, gitlab.org, SF.com, or whoever else comes next can host development versions.

https://www.softwareheritage.org/

They only do archiving. Hosting projects that are under development is not in their mission. https://www.linuxfoundation.org/ looks like a better match.

There is a need for an organization that is willing to host established but small and unfunded projects like libtiff, libpng, zlib, etc., and give them some minimal organizational backing in the interest of continuity (so no github). Somewhat similar to, but more general than, what the Network Time Foundation is doing for ntp and related projects.

Re: Libtiff goes offline

#107

Post by dagw »

fdgdasfadsf wrote: post #82
banachtarski wrote: post #7

Tiff? That is a format I haven't heard in a long time. edit: to everyone replying. TIFF is awful. We have lossless compression now (read PNG) which is at least a billion times better. We shouldn't use it for anything in this day and age. Hell, just DEFLATE your TIFF and call it a new format. It will be better than TIFF

Can we have multichannel 16bit PNGs now? Can PNGs hold 3D images? If so awesome I can drop TIFF at last. Not all images are taken by cameras using 3 channels.

Can we have multichannel 16bit PNGs now?

The PNG-format supports them (up to 4 channels) however not all apps know what do with them.

Re: Libtiff goes offline

#108

Post by gpvos »

banachtarski wrote: post #77
cjhanks wrote: post #64

Earlier quoted context omitted.

TIFF supports many useful features for processing very large images. Tiled compression, storing channels in contiguous hyperplanes or on a single image plane, multiple levels of detail, custom compression codecs (lossless or lossy), sparse images, arbitrary bit widths, and permits storing arbitrary metadata with the data. Viewers of libtiff often treat it like PNG/JPEG, but good Tiff viewers can leverage this functio…

I don't doubt that you can have a library that provides all those features. All those features can exist for any lossless image format. My point is that as far as comparing image formats goes, the capabilities of the frontend library isn't a useful metric for evaluating the format itself which, in my opinion, can optimize for the following traits: 1. On-disk size 2. Compression/decompression speed 3. Access speed (fo…

> All those features can exist for any lossless image format.

Yes, but for most image formats they aren't defined. They are for TIFF.

The problem, of course, is that if you use an exotic TIFF feature, very few TIFF readers will understand you.

Re: Libtiff goes offline

#109

Post by flukus »

pferde wrote: post #99
flukus wrote: post #89

Earlier quoted context omitted.

> You still need a protocol for determining the history. Is this a real problem or a theoretical problem?

Such problems are always theoretical, until they suddenly become real, and you're happy that someone years ago has thought of that possibility, and left behind a way to solve them...

And many, many more problems are theoretical and remain theoretical forever.
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