The difference is that TIFF is read and written by dozens of ad'hoc software packages. Some use 'libtiff' - but most do not.
True, but the use (or lack thereof) of libtiff has NOTHING to do with the quality or reliability of the TIFFs that are produced. It has to do with the use of features that have long been considered deprecated and/or invalid - but some folks just keep on using them :(.
If you look at a format like PNG, hardly anyone reads and writes it using their own code - almost everyone uses libpng - so there are no problems with PNG compatibility.
Actually, the fact that PNG is MUCH simpler and MUCH newer than TIFF is the reason - has NOTHING to do with libpng.
So, I think what is needed to make a reliable file format is to provide a well written library for reading and writing the files that's freely available and properly maintained on every modern platform FROM DAY ONE.
That's definitely an option - BUT that means that it would have to have a flexible enough license to be used in both GIMP and in commercial solutions...and more importantly, it means someone has to be willing to take that project on ;).
But again, I will point out that the issue with TIFF is NOT the creation of files that are invalid according to spec, it's the use of unsupported features of the spec...A standard library wouldn't help there - since, for example, libtiff can be used ot make such TIFFs...
Another problem with TIFF is that it's easy to extend.
And that's a requirement for the future of XCF as well...
Well, if you have programs that invent tags that say things like "What follows is a block of pixels in MacPaint format", or "If this tag is set, the pixels are stored bottom-to-top instead of top-to-bottom" - then ignoring a tag you don't recognise results in a very screwed up image.
True. But how is this different from what we are envisioning for XCF? If a given XCF reader doesn't support all features of the format, you can get the same result...
Leonard -- --------------------------------------------------------------------------- Leonard Rosenthol <mailto:leonardr@xxxxxxxxxxxxx> <http://www.lazerware.com>
