[Bug] Import Layer Flipping

[TuXiCs]

System

UVtools v5.2.0 Arm64
Operative system: Darwin 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:28:30 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6030 Arm64
Processor: Apple M3 Pro
Processor cores: 11
Memory RAM: 7.20 / 12.32 GB
Runtime: osx-arm64
Framework: .NET 9.0.8
AvaloniaUI: 11.3.4
OpenCV: 4.11.0

Sreens, resolution, working area, usable area:
1: 1800 x 1169 @ 100% (Primary) (On this)
    WA: 1800 x 1125    UA: 1800 x 1125

Path:       /Applications/UVtools.app/Contents/MacOS/
Executable: /Applications/UVtools.app/Contents/MacOS/UVtools
Loaded file: MUG3_plain_tub_c2c3c4.ctb [Version: 5] [Class: CTBEncryptedFile]

Printer and Slicer

• Printer: Elegoo Mars 4 Ultra
• Slicer: Chitubox Pro 2.0.8

Description of the bug

I export a layer as PNG to edit it externally in GIMP.
When i import the PNG (edited or not) it is horizontally flipped in UV tools and does not align with the upper layers anymore.
Even if i import the same unedited layer right back in UVtools it is always oriented in the wrong way, no matter the orientation of the input image.

How to reproduce

Open ctb. that has easy to spot side differences.
Export a layer as image to PNG
Import that layer and replace the current layer with it.
Keep Cool

Files

UVTools_bug.zip

[sn4k3]

I guess you are using this dialog:?

The dialog flips image to match the printed output and not preserve the original image in most cases.
Make sure to use both "None" as shown on screenshot to keep original image.

If you want raw export you can also use File -> Extract

[TuXiCs]

Yes this dialog to export and the Actions -> Import Layers (with ImportType: Replace) to import the exported file.
I tried it with both dialogs turned to none, but when importing the orientation of the imported image does not match the image i selected (plainly by comparison in png viewer and uvtools). I tried it with flipping and without, both funnily enough turn back to the wrong orientation.

[sn4k3]

Ok I will check it. In meanwhile try with File -> Extract. I guess you will get same problem.

[sn4k3]

I can't reproduce this.
What I tried:

• Actions -> Export layers
  • Flip and rotate: None
  • Export
• Actions -> Import layers
  • Load the layer0000.png
  • Insert at 0
  • Import

Imports the layer as it should, no difference between layer 0 (imported) and 1 (previous the 0 / original)
Replace does the correct outcome too.

If I import your layer_flip001.png it imports as it should (flipped) as your image is flipped

Exported image (None, None):