Iron Man, Thor, Captain America, and Hulk from Marvel HD Wallpaper

The image is divided into four quadrants, each featuring a minimalist depiction of a superhero's head. The top left shows Iron Man's golden mask on a red background. The top right displays Thor's helmet and blonde hair on a blue background. The bottom left features Captain America's mask with a white 'A' on a blue background. The bottom right shows the Hulk's green, angry face on a green background.