Bug 487103

Summary:	EXR with XYZ channels are incorrectly visualized
Product:	[Applications] krita	Reporter:	CodingInProgress <andy.codinginprogress>
Component:	File formats	Assignee:	Krita Bugs <krita-bugs-null>
Status:	REOPENED ---
Severity:	normal	CC:	halla
Priority:	NOR
Version First Reported In:	5.2.2
Target Milestone:	---
Platform:	Microsoft Windows
OS:	Other
Latest Commit:	https://invent.kde.org/graphics/krita/-/commit/ca7b914a8a9d7e0ab384a40fd80c80d9014a47fb	Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	EXR file with XYZ channels, which are incorrectly visualized in Krita

Description CodingInProgress 2024-05-16 12:56:37 UTC

Created attachment 169530 [details]
EXR file with XYZ channels, which are incorrectly visualized in Krita

SUMMARY
EXR files with XYZ channels are not visualized correctly. I would assume that the XYZ channels were converted directly to RGB, which is what happens for instance in Blender.

STEPS TO REPRODUCE
1. Open the attached file

OBSERVED RESULT
The word 'Green' is shown in white.

EXPECTED RESULT
- Top left, word 'Red' is stored in 'X' channel
- Middle right, word 'Green' is stored in 'Y' channel
- Bottom left, word 'Blue' is stored in 'Z' channel
The expected result is to see the word 'Red' in red (X channel gets converted to R channel), and the same for the other channels.

SOFTWARE/OS VERSIONS
Windows: 11
Qt Version: 5.15.7

ADDITIONAL INFORMATION
I originally reported it to Blender, but it turns out that it seems to be a Krita bug.
https://projects.blender.org/blender/blender/issues/121841

Comment 1 Halla Rempt 2024-07-04 09:04:50 UTC

Maybe the actual problem is that Krita infers that the image is RGB, while the layer is loaded as XYZ.

https://invent.kde.org/graphics/krita/-/merge_requests/2182?commit_id=ca7b914a8a9d7e0ab384a40fd80c80d9014a47fb has a partial fix. The problem is that in the layer thumbnail blue and red still are not visible, but they become visible on a round-trip converting the layer to rgb and then back.

The thumbnail in the recent files screen also shows only green, but in gray.

When saving the image after round-tripping, it's needed to also convert the image colorspace to xyz, since we cannot apparently save an exr image with layers in a different colorspace from the image, which I thought was possible.

Comment 2 Halla Rempt 2024-07-04 09:07:01 UTC

Git commit ca7b914a8a9d7e0ab384a40fd80c80d9014a47fb by Halla Rempt, on behalf of Rasyuqa A. H..
Committed on 04/07/2024 at 08:36.
Pushed by rempt into branch 'master'.

EXR: Import: add XYZ to top level channel names

M  +9    -3    plugins/impex/exr/exr_converter.cc

https://invent.kde.org/graphics/krita/-/commit/ca7b914a8a9d7e0ab384a40fd80c80d9014a47fb

Comment 3 Halla Rempt 2024-07-04 09:24:51 UTC

So, while there's a partial fix, there still are problems, so let's keep this bug open.