New wallpaper.

So I'm currently and sort of offgoing working on a new wallpaper. This TIME IT's DIFFERNT THOUGH. it's not my average get an image extract it and then get cute brushes to make it sazzy. But this time I have a full image wallpaper that I want to work at problem with it is it's sort of distorted and pixelated. MY IDEA is to paint it all over like a lot of people do. BUT I haven't the first clue how to do that since I've never done it. Tips?

End