Export of one photo has major corruption of image

I’ve been reprocessing some old photos in PhotoLab 4 and having no problems except for one image. It looks fine inside PhotoLab but when I export it I get giant black stripes and a couple of odd artefacts which appear to be related to one of my uses of the Repair tool.

Here’s the photo in PhotoLab showing the Repair tool masks with the offending one selected.

And here’s the exported version. I tried two different JPEG export presets (quite different sized output) and they show the same issue.

I’ve never seen anything like this before.

Do you also get the stripes when you disable/remove the repairs?

Good point. Yes, and without the smaller glitches.

Do you also get the strips if you export from a real copy of the file? Maybe the file is damaged?

I just opened it with macOS Preview and Affinity Photo and both render it fine.

could you upload the raw file and we give it a go?

Did you do the repairs before you cropped the image? This is not recommended.

Try making a virtual copy, resetting it, then cropping, etc before doing any repairs or local adjustments.

Why, and by whom? I don’t see that it should make a difference since crop is just constraining the visible bounds of the image.

Just curious, since I’ve never seen this particular bit of advice before.

This topic has come up several times from people who have made corrections, then made geometric changes. Apparently, repairs and local adjustments take the visible image as the source for their coordinates, not the original image.

Ok, geometric changes before repair I can see, but crop shouldn’t make a difference, unless cropping after a repair moves source areas outside of the crop, and that would be quite odd.

Then again, since source points can be moved, I wonder what the behaviour is if a crop boundary falls between a source and destination?

So many potential bugs … :slight_smile:

Yes, some repairs were done before the crop. But I turned off the repairs and still get the stripes. Surely with them turned off they should have no bearing on the output?

So I made a virtual copy, reset, and exported. No black stripes.

I cropped to 3200x1800. No black stripes.

I turned on DeepPRIME (at 25). Black stripes, but thinner than the originals.

So it’s something in the demosaicing I think. Here’s the original:
_IGP1963.dng (8.7 MB)

It’s probably worth noting I see occasional glitching in the DeepPRIME preview window, too.
Screen Shot 2020-11-19 at 14.53.34

Tried several things with the file. I get no black lines in DPL4.
-> Please also post a sidecar with which you get the issues.

Maybe re-download DPL and replace your app?

I think I’d rather DxO weigh in on this first. “Turning it off and on again” shouldn’t be required. I’ve processed 23 other photos from the same camera, all with DeepPRIME, and all of them are fine.

Here’s the .dop file. I thought there would be two, but I guess one file contains both copies.
_IGP1963.dng.dop (27.2 KB)

Have you set preferences to use a GPU? Some GPUs are not powerful enough and need to be turned off as explained in the notes in the preferences dialog.

Thanks, that does seem to be it. I had switched it to use my “partially supported” Intel UHD 630 integrated graphics as that turned out to be markedly faster than CPU on my Mac mini.

Switching it back to CPU cured the stripes and again switching to GPU brings them back. I had not read “stuttering and/or errors” to mean “corrupt output”. Live and learn I guess.

Hopefully the point will be moot when my M1-powered MacBook Pro arrives next month. :grin:

Glad we got to the cause of your issue :slightly_smiling_face::+1:

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