Overexposure and bleeding effect

[cgidesign]

I used my glow / bloom example also to test blend mode bugs and fixes in Krita.

As you might know, Krita up to version 5.2.9 has various issues with blend modes if you are using 16bit float or 32bit float color format.

Krita 5.3 alpha nightly from 2025. Feb. 04. got a big bugfix for those.

If you like to test it yourself here are the files I used to test:

Bloom-Effect_Testfiles.zip

The zip includes an 8bit Krita document and a 16bit float document.
If you use Krita 5.2.9, load the 16bit float document and active the “Bloom Effect” layer, you will get a weird dark result (this is one of the bugs in the blending modes).
If you use the latest Krita 5.3 alpha, the Bloom Effect layer will work correctly.

Here is the thread about the topic:

[needs testing] Fix blendmodes in Float16 and Float32 color spaces

Hi, all! I’ve spent the last two weeks rewriting and fixing the blendmodes so that they would work correctly in Float16 and Float32 spaces. Before this patch, converting the image with non-trivial blendmodes (or layer styles) into F16/F32 color space could cause color artifacts (some pixels could randomly become extremely bright or completely black). That happened because of the unlimited nature of floating-point color spaces, so the color values could sometimes become negative or NaN or infini…