Exported TIFF has artifacts not seen in darkroom

[lphilpot (Len Philpot)]

Windows 11
darktable Oct. 16 weekly build 4.1.0+565~gfc50dbc5a (same issue seen with 4.1.0+427~g90b964f88)
Canon CR3 image

It may be something I’ve done – goodness knows I’m no darktable expert – but I’m seeing some artifacts in the TIFF that aren’t visible (as strongly, at least) in the darkroom. See 100% and 200% screenshots, note the fringing around the leaves against the sky.

100% darkroom

100% TIFF

For clarity, here’s 200% percent:

darkroom

TIFF

Now once again I’m far from expert and there are certainly some artifacts in the darkroom view, but they’re vastly worse in the TIFF export. The difference between the two is what concerns me, since I’d expect them to look the same.

My export settings

CR3 and XMP

IMG_5021.CR3.xmp (14.7 KB)
IMG_5021.CR3 (30.2 MB)

I see the same TIFF artifacts in XnView MP, Fast Stone Image Viewer and Affinity Photo, so they’re real. No changes have been made to my DT config recently and I don’t recall seeing this before. I’ve not opened a github issue in case it’s something I’m doing wrong (but can if it’s deemed a bug).

Thanks.

[g-man]

Try with high quality resampling to yes.

[priort (Todd Prior)]

I don’t know if it is predictable in every case but I have posted on something similar before. Apparently the export pipeline is not the same as the display preview pipeline to the extent that deviations can occur esp when zooming and how that impact data in the ROI used to calculate the display. The last one I saw were some artifacts that appeared different at different zoom levels and also were not the same in the exported image…

Noted here

Something WRONG with darktable 4.1.0~git272.5a1a1845-1 clipped highlights

This is why I asked… I noted that using the image from the OP. The displays are not showing the same image and it can change with zoom in the center or main preview while not in the preview/zoom nav preview in the upper left that you use to pan. I used the image with only a small set of adjustments. I started by changing the raw white point to the value stated in the meta data…ie around 15383 I think. Okay so now filmic only at all v6 defaults and with exposure using auto exposure ( I think it …

[priort (Todd Prior)]

Interesting… where does pixel type come from… I don’t have that in my export dialogue???

[lphilpot (Len Philpot)]

@g-man

Try with high quality resampling to yes.

I did before posting, but there was no difference.

@priort

Interesting… where does pixel type come from… I don’t have that in my export dialogue???

Dunno. This is Bill’s weekly build…?

Thanks.

[priort (Todd Prior)]

I just looked through your edit…to me it seems like your contrast eq is the issue… I looked at the mask and the areas masked are showing up in your export but not your display I think…at least when I disable it the artifact goes away from the export…

Contrast eq mask…

[g-man]

@lphilpot

I did before posting, but there was no difference.

Can you post it?

[jorismak]

@priort is pixel type a thing just for tiff and you are looking at something else in your export window ?

@ topic : as if the mask is somehow causing an alpha thing (opacity ) written in the tiff?

You should be able to spot that in affinity …

[apostel338 (HP)]

@priort

seems like your contrast eq is the issue

Yes please. I don’t know, why the artifacts are stronger in the TIFF, but in general I would try to avoid masks with such hard edges at all. Your photo is full of these artifacts, in your sample crop it’s just a little more visible than in other places.

Try increasing feathering radius. Should give you the same overall visual effect but without the problems of the hard edges.

[priort (Todd Prior)]

The OP just has a setting in their tiff export that I don’t seem to have…just wondering where it came from??

[lphilpot (Len Philpot)]

Actually, I was fiddling around with CE trying to get a bit more contrast out of the wood building, but I thought I had turned it off since I abandoned that idea. Apparently my allergies / sinuses were affecting me more than I thought last night. But your suggestion is well taken. I usually refine masks more, but I thought that was disabled.

[lphilpot (Len Philpot)]

It was the CE / mask, but here are two screenshots with no CE / mask: One without high quality resampling and one with. There’s basically no difference.

No HQR

With HQR

There’s still a little bit of a hard edge but that could be something else entirely. I had also run into issue with filmic / preserve chrominance on previous images so I had disabled it. Setting it back to maxRGB might have helped a little.

[priort (Todd Prior)]

My go to is dehaze preset of diffuse and sharpen … maybe give that a try