Bug 441795

Summary:	Regarding the issue of exporting exr
Product:	[Applications] krita	Reporter:	楊景貴 <issacsopp>
Component:	File formats	Assignee:	Krita Bugs <krita-bugs-null>
Status:	CONFIRMED ---
Severity:	normal	CC:	alvin, amy, halla
Priority:	NOR
Version First Reported In:	5.0.0-beta1
Target Milestone:	---
Platform:	Compiled Sources
OS:	Microsoft Windows
URL:	https://krita-artists.org/t/regarding-the-issue-of-exporting-exr/28281
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	This is my test file tev preview of the exported KRA Exported EXR file opened in Krita and then split alpha, which looks different

Description 楊景貴 2021-08-31 03:08:10 UTC

Created attachment 141174 [details]
This is my test file

SUMMARY


STEPS TO REPRODUCE
1.I followed the instruction below, but the result is incorrect
How to save a PNG texture ...: 
https://docs.krita.org/en/reference_manual/layers_and_masks/split_alpha.html
image : https://krita-artists.org/uploads/default/original/3X/5/e/5edaba938de0e53ebb45ff7ca086637b4fdf0255.png

2.Open the exported EXR in bledner and GIMP.

3.Turn off the alpha channel after GIMP is turned on
Blender only outputs color information (equivalent to turning off alpha)

4.You will see wrong black borders and abnormal black translucent patches

in Blender image :https://krita-artists.org/uploads/default/original/3X/0/1/0120e6370492a8bb23214944a97ff8269c6d4315.jpeg

in GIMP image : https://krita-artists.org/uploads/default/original/3X/3/4/34494022ce60523678a06a322864c071d0225ae7.png

OBSERVED RESULT
These black edges are the outline of the alpha, and above, I deliberately painted a light gray on the alpha to represent translucency. After the export, the light gray area seems to be darkened, so my observation is
When the color channel is output, it will be superimposed and mixed with alpha, which will affect the color channel information.

EXPECTED RESULT
After output, you get the clean color channel and alpha as in krita
I think there must be an option to output it without changing any information in the file channel.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

Comment 1 amyspark 2021-09-03 22:38:06 UTC

Commit 91bbbd5ffd with OpenEXR 2.5.5.

tev shows our exported EXR has block artifacts round the bird's borders.

Comment 2 amyspark 2021-09-03 22:38:50 UTC

Created attachment 141279 [details]
tev preview of the exported KRA

Comment 3 Alvin Wong 2021-09-05 13:22:59 UTC

Created attachment 141313 [details]
Exported EXR file opened in Krita and then split alpha, which looks different

Curiously, if I open the exported EXR file back in Krita and split alpha into mask, the image looks completely different from what the Blender and GIMP screenshots show...