GIMP 2.99 /Python3 Gaussian Blur different results from script and GUI

As the title says:
Using a Gaussian blur in the GUI does not give the same results as in a (python) script.
How can I achieve the same results in a script?

The situation is this: I try out a blur setting via GUI so it looks the way I want it.
Then I enter the same settings in my script - but the result looks very different.
So the question is: how to resolve.

It really feels like there are two different Gaussian blurs - one for GUI and one for scripting.

Looking in the procedure browser, there are several gaussian blur alternatives. Assuming you used plug-in-gauss, then I see in app/pdb/plug-in-compat-cmds.c that the horizontal and vertical parameters are multiplied by 0.32. This is most likely a leftover from conversion of the pre-gegl legacy gaussian plug-in to have similar results as the gegl filter.

So, yes, you are right, the parameters in the plug-in are probably based on the legacy plug-in, that GIMP internally translates to similar values for the gegl filter.

Ideally we would have an easy way to access the gegl filters and their parameters directly, but nobody has gotten around to doing that yet.

AFAIK the only difference is the “units” and there is a ratio of approximately 6 somewhere (the PDB function uses the Gimp 2.8 units, so if you have a Gimp 2.8 somewhere you can compare).

You can call the GEGL function but this is somewhat contrived. Some example code here

Thanks for clarifying.
I’ve tried with plug-in-gauss-rle now. The results are much closer to the GUI.

Thank you.
I thought it would be easier to access GEGL plug-ins in GIMP 2.99.

Nothing impossible, but I think we would need some additional Python module to make this really easy.