Bug 514700

Summary: Severe lagging with certain brushes in non-rgb color spaces.
Product: [Applications] krita Reporter: C. Shen <pentalimbed>
Component: Brush enginesAssignee: Krita Bugs <krita-bugs-null>
Status: CONFIRMED ---    
Severity: minor CC: info
Priority: NOR    
Version First Reported In: nightly build (please specify the git hash!)   
Target Milestone: ---   
Platform: Microsoft Windows   
OS: Microsoft Windows   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description C. Shen 2026-01-16 16:28:50 UTC 
SUMMARY
Severe lagging with certain brushes in non-rgb color spaces.

STEPS TO REPRODUCE
1. Create a new image in CMYK or LAB color space
2. Install and use the first brush from https://krita-artists.org/t/memileo-impasto-brushes/92952
3. Paint on canvas

OBSERVED RESULT
Seconds delay from painting to brush effecting

EXPECTED RESULT
Less lag, as much as in standard RGB space

SOFTWARE/OS VERSIONS
Windows 11
Krita 5.3.0-prealpha (git 38b517c)

ADDITIONAL INFORMATION
Comment 1 Wolfgang Baer 2026-01-17 07:58:02 UTC 
Confirmed (Ktita 5.3 on Windows 10)
Any other color space than RGB/Alpha leads to severe lag.
Comment 2 Wolfgang Baer 2026-01-17 08:00:45 UTC 
Tested with memileo brush.