darktable-org / darktable-org/darktable
Downscaled preview not accurate when using retouch after orientation
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- Dominant language
- C
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Description
Describe the bug
When using retouch after using orientation to rotate an image -90 or 180 degrees, the downscaled preview (<100%) is not accurate. Areas that should be retouched show up anyway. This is especially apparent when retouching small high-contrast artefacts. When zooming to 100% the problem disappears. Export is also not affected.
My current workaround is to use the rotate and perspective module to rotate my images.
100% zoom / before retouch
100% zoom / the retouch shapes
100% zoom / retouched
42% zoom / retouched
39% zoom / retouched
36% zoom / retouched
The effect is different depending on the zoom percentage.
Steps to reproduce
- Rotate a raw (didn't test Jpeg) photo -90 or 180 degrees (90 seems to be unaffected in my case) using the orientation module.
- Retouch a high-contrast artefact using the healing tool with a brush. Make sure the shape fits snugly around the artefact.
- Zoom to levels below 100% to see the artefact partially appear again.
Expected behavior
Show an accurate downscaled preview of the retouch edit after rotating.
Logfile | Screenshot | Screencast
Changing these settings did not seem to affect anything.
Commit
No response
Where did you obtain darktable from?
downloaded from www.darktable.org
darktable version
4.8.1
What OS are you using?
Windows
What is the version of your OS?
Windows 10.0.19045 Build 19045
Describe your system?
No response
Are you using OpenCL GPU in darktable?
Yes
If yes, what is the GPU card and driver?
NVIDIA GeForce RTX 2070 SUPER, 8 GB, Driver 32.0.15.6081
Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip
No response
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the issue by applying orientation to a raw image, retouching a high-contrast artefact with the healing tool, and comparing previews below 100% with the 100% view and export. Trace the orientation and retouch preview paths; done means the downscaled preview remains accurate after -90 or 180 degree rotations without changing the unaffected export.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- c
- Domain
- computer-graphics
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100