Le 03/11/2018 à 21.10, Michael Below a écrit :
For me, the main point is that darktable preserves the image quality of
an input image as far as possible, even when it is in a lossy format
like JPEG.
The idea of re-using quantisation tables can make sense, I am not a
programmer. But re-using the "quality settings" as presented to the
user seems a bad idea.
Don't worry about that. "Quality settings" in that context is used to
keep words simple. They most certainly exactly refer to "quantization
table": a set of numbers that has the properties you wish.
I seldom edit JPEG, but when I do I'd actually appreciate the feature,
because it totally makes sense, like in children story "Goldilocks and
the Three Bears
<https://en.wikipedia.org/wiki/Goldilocks_and_the_Three_Bears>":
* blindly exporting at higher "quality" just wastes space,
* blindly exporting at lower quality deteriorates much more than from
a clean source and is thus undesirable,
* exporting with the exact same quantization tables makes best use of
existing data and storage, is optimal in a number of cases (local
changes, crop, no dramatic luminance change). And in all other
cases, the user can always choose a different quality at export time.
I'm confident that implementing this change would solve the reported
problem. (Not expecting that anyone will do it any time soon, still, and
it will probably be a long time until I find some time to offer myself
to learn enough about darktable internals and implement it.) Feedback
welcome.
Cheers,
--
Stéphane Gourichon
____________________________________________________________________________
darktable user mailing list
to unsubscribe send a mail to [email protected]
