Denoised transparent background

[Arch-Cad]

Hi,
I use LuxcoreRender-Blender Addon for Arch-Viz, just for a few month and I am highly impressed about the output results!!!
There is one point, I am not able to handle, maybe due my limited experience.
When I need render results with transparent backgrounds, I activate camera transparent film.
The combined view has a transparent background. When I switch to denoised mode, the background is no longer transparent, so I cannot use the denoised Image, when a transparent background is needed.
Is there a workaround in the Luxcore setting?
Can it be handled in Gimp?
OS: Windows 10
Kind regards

[B.Y.O.B.]

You can use the Blender compositor.
Enable the Alpha AOV in the render layer settings and feed it into the alpha output of the compositor.
I can describe it in more detail if needed.

[Arch-Cad]

hesitate to ask… but would be great, if you could describe the Blender settings a little bit more detailed. Use Blender 2.8 Version
1.) Activated “Alpha” in the AOV setting.
2.) Opened the Composite Editor Window, which is empty…...

[B.Y.O.B.]

Oops, you don't need to enable the Alpha AOV.

Here the detailed steps:
- Enable "use nodes" in the compositor menu bar
- Recreate the node setup like in the attached screenshot
- Render, and make sure to end the render with a halt condition in the render settings (not by pressing escape), for example by specifying the amount of samples or the time to render for (you can adjust these during the render). This is necessary so the compositor is executed after the render, which does not happen when pressing escape to stop.

[Arch-Cad]

You made my day B.Y.O.B !!
It works!! Even with Bidir/Metropolis, which I use for more complex scenes, like glass interior behind (Architectural) glass windows.
Many thanx!!!!!

[wasd]

This is necessary so the compositor is executed after the render, which does not happen when pressing escape to stop.

If you change something in compositor node setup, then compositor will run. E.g. uncheck and check back "Use Alpha".