IPhone 4s home screen background go a few mm's too low?

All the iPhone 4s background that you can get on the internet don't seem to align properly with my home screen. All the pictures are 640x960 but when they have bases of where the icons go, etc, they're a few millimeters too low below where they actual icons are.

For example, I used this picture;

image

and when I used it as a background, not resizing it or anything, it comes up like this;

I have reduce motion on so it's not that, but they all seem to go below the place they're supposed to. Why is this?

Its because the way ios7 zooms in on backgrounds