
I'm trying to batch convert some pngs with transparent background to jpeg format with black background color, but XNViewMP only converts them to white background files.
I only found this posting, which is from 2018, telling me, there might be an option to select the background color, but I don't know all the terminology to find that specific option.
I asked chat-gpt too, but after 20 minutes of hallucinating answers, I did not had a solution.

I think this must be too simple so I cannot find it...