Edit: I made a little research and I found out that it needs a .blp image. Ok, I converted my .JPG image into a .TGA and then with wc3 Viewer I converted the .TGA image into a .BLP picture. But something didnt work out like it supposed to. When I converted the .TGA into .BLP it was 0kb large... thats impossible. Even so, I imported it into my map and when I try to use it the game crashes.. can somebody help me?
Edit2: Ok, I found out how, I converted the picture with war3 Model Editor and than I imported it into my map..

Edit3: I cant figure out how to show the picture to only one player
