Thanks for answering.
I did not shoot it myself, got it from the owner in jpg, not more than 1200x800 in low resolution.
Since I cannot change the photo, I will ty to do as you say in Photoshop.
Even if I will paint it, I find it best to have the photo as good as possible to start with.

The result will be A4 in 300 dpi before I print it.