I often go hiking and have hundreds of photographs. Recently as a new hobby I've begun digitally altering the best ones (fixing colors, etc, basic stuff). That morphed into completely redoing them, adding elements, applying filters, and a fair amount of manual brush-painting above the image.

I attached a pretty typical transformation as an example. They're all landscapes. The original is attached too.

I'm only doing this for fun, but am wondering what it's called? I'm not starting with a blank canvas so digital painting isn't right, it's not graphic design... but it seems like just photo manipulation isn't quite the right name either. I just want to be able to answer succinctly when someone asks what it is as a hobby.