Batch converting images as brushes

[Ofnuts]

(10-03-2019, 11:16 AM)Espermaschine Wrote: I have 150 png images with transparency.
They come from a PS .abr file i exported to single png files with a program called abrMate.

I did this because i dont need all the brushes but only some.


How do i batch convert 150 files/layers at once so they are converted to grayscale and a white background is added ?

I have Bimp installed but that doesnt seem to do what i want.
Is there no plug-in/script that exports abr files as Gimp brushes ?

1. Use my interleave-layers script to add a white background to each layer
   
2. Image>Mode>Grayscale
   

Then, things get a bit sticky because the default file-save that I use in a script doesn't work on GBR because each file wants a spacing. If you aren't too much of a hurry I can make a GBR-specific derivative of my script.