Bug 443797

Summary: Lots of G'MIC filters show stair-like edges on result
Product: [Applications] krita Reporter: acc4commissions
Component: G'Mic for KritaAssignee: Krita Bugs <krita-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal CC: amy
Priority: NOR    
Version First Reported In: git master (please specify the git hash!)   
Target Milestone: ---   
Platform: Compiled Sources   
OS: All   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: preview
test file

Description acc4commissions 2021-10-15 18:51:34 UTC
Created attachment 142482 [details]
preview

SUMMARY
git 10788d9

Lots of G'MIC filters show stair-like edges on result, when the painting is drawn in transparent layer.

STEPS TO REPRODUCE
1. 
2. 
3. 

OBSERVED RESULT


EXPECTED RESULT


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 2021-10-15 18:56:06 UTC
Hi! Can you share a .kra or the filter configuration? Also, have you tried reproducing it with previous versions of Krita (4.4.x, earlier would be better too)?
Comment 2 acc4commissions 2021-10-15 19:16:00 UTC
Created attachment 142483 [details]
test file
Comment 3 acc4commissions 2021-10-15 19:18:27 UTC
This also seems happen in 4.4.8, although there are not a lot of filters that exist in 5.0 alpha and I'm not sure the result is the same. I tested 'This Edges' with default settings untouched in 4.4.8.
Comment 4 Bug Janitor Service 2021-10-16 04:35:33 UTC
Thanks for your comment!

Automatically switching the status of this bug to REPORTED so that the KDE team
knows that the bug is ready to get confirmed.

In the future you may also do this yourself when providing needed information.
Comment 5 amyspark 2021-10-21 16:52:03 UTC
Confirmed on 4.4.8 and Paint.NET 4.3.2 with the following filter:

Annular_Steiner_Chain_Round_Tile 800,1,0,0,100,0,100,12,0,1,0,0,0,255,0,255,255,0,127,0,0,255,127,0

Compare with

fx_taquin 7,7,0,50,5,0,0,0,0,255,0

which shows some filters do support alpha channels.

As it is for upstream to review its filter definitions, I'll mark it as UPSTREAM.