I've tried this but it doesn't help: Image resize under PhotoImage
I already have this:
import tkinter
root = tkinter.Tk()
root.attributes("-fullscreen", True)
photo = tkinter.PhotoImage(file="image.gif")
img1 = tkinter.Label(root, image = photo)
img1.pack()
root.mainloop()
This works but my image doesn't take up the full screen and I wanted to know how to resize it to full screen.
I realised it is not possible to do this and I will try to use PIL. Thanks to @BryanOakley for helping me with this question.