Wrong composite space selected for PNG imports
GIMP version: GIMP 2.10.14
Operating System: macOS
Package: Installer from gimp.org
Description of the bug
test-alpha.xcf Please describe your issue with details. Add screenshot or other files if needed.
Reproduction
Is the bug reproducible? Always
Reproduction steps:
- Open the attached PNG in Gimp, with alpha transparency (image is an opaque white rectangle with a 50% opaque black rectangle overlaid, partially covering the white rectangle – created with Gimp 2.8.22)
- Create a new layer with white background
- Move the new layer to be behind the imported image
…
Expected result: There should be one flat grey rectangle, with a white surround
Actual result: The rectangle has 2 different shades of grey, and is darker over the intersection of the two original rectangles.
Additional information
The PNG layer is given composite space "Auto" (linear) on import. Changing the composite space to "Perceptual" fixes the issue, but must be changed every time an image is imported. In any case, the default is wrong.
Displaying the PNG image in a web browser with a white background, or e.g. previewing in a desktop folder view invariably shows the image correctly.