Stacking with pixelmath

Two questions about pixelmath:
Is it possible to stack two or more (calibrated)images with pixelmath and what formula do I need?
And how do I combine starless and stars only picture separated with StarXTerminator?

Hello.

Maybe this tutorial could help you:

I cannot find the answer to my question in that tutorial.

So how do I take the average of 2 images, is it (A+B)/2 ?

Yes, this is it.

Thanks. Still need to figure out how to implement screen blend mode in pixelmath.

There’s no screen blend in the PixelMath.

Good to know, thanks.