Sounds complicated, but possible. (Only, when you go several ways, the already not perfect quality will weaken even more, which is, why I prefer the direct desktop ones. . .)
While for many times now the simple original desktop pics were doing fine. . .I can even bring them up again, whenever I feel like, for whichever place, only this one does not work here. It does on other places though.
I wonder, if it has to do with the fact, that it was done via digital camera, while the others were not or just taken from the internet or so. . .
However, there is no rush, and I can as well stay without the pic there or use the old one again.
Anyhow, I will try the path, you mentioned.
Thanks for encouragement!