Artifacts with xtrans white balance preprocessing
Issue #85
resolved
As reported in a recent discussion on pixls.us, there’s a bug in xtrans white balance preprocessing. This bug also affects ART (tested yesterday with fresh build from source).
A fix has been merged in RT dev branch: https://github.com/Beep6581/RawTherapee/commit/d4fc4dc083b59165f5ae731099472406dc734105
Comments (8)
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repo owner
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reporter
Fine, I’ll test when you push a change. Thanks.
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repo owner
I just pushed it. Let me know if you find anything weird – thanks!
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reporter
It’s much better now. However, it still leaves some faint artifacts. If I switch to mono demosaicing and then back to xtrans demosaicing, those artifacts disappear, and I’d say the image is even a bit sharper on some images.
Here’s a screenshot from the pixls.us forum, showing the artifacts zoomed in. Left is new ART, right is also new ART but after switch back and forth between mono and xtrans demosaicing.
But it’s heavy pixel peeping, and as it is now I think it is good, and already an improvement. -
repo owner
This change of behaviour is indeed a bug. The history of which demosaicing algorithms were activated before the current one should not matter. I will look into it, thanks!
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reporter
Your last change isn’t good, see the screenshot below, left is default, right is switching to mono and back to xtrans domosaicing:
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repo owner
should be fixed now
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repo owner
- changed status to resolved
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I’m not sure the fix is actually a fix, rather than a workaround for that specific image. If the camera WB were off, it would produce the same artifacts.
More in general, I don’t think adding an extra tool “WB to use for raw preprocessing” goes in the spitit of ART, which is to be a raw processor for dummies, not for power users
Anyway, I will soon push a change to the pipeline order, so that WB is performed before demosaicing in all cases. I think this is a better solution (I mean better for ART, not necessarily better in general)