Adaptive window resizing

I often open a small pic in EOG, then switch to a larger one, and it gets scaled down to the size of my window. So I have to resize the window manually and so on. It would be great to have the window behave adaptive to the image. There should be three modes in settings:
1) Do not resize window automatically
2) Only increase window size
3) Always resize the window //if you view pics of different size, you'll have to chase your control buttons all over the screen, so mode 2 is preferable