When I open a photo in eog I can easily zoom with the mouse mouse wheel. This is kind of nice but since I have a touchpad with two-fingered scrolling and horizontal scrolling I'd rather scroll in the image and zoom by using Ctrl+Mouse Wheel?

I basically want the same behaviour as in evince:
Horizontal Scroll and Normal Scroll navigate within the image and Ctrl + Mouse Wheel zooms in and out.

Is this possible somehow?

[EDIT]
I just figured out that what I want is already implemented: I can pan the image by using Ctrl + Mouse Wheel. This is fine as it is the behaviour I want only with the Ctrl inverted.
But I cannot pan to the left. Up, down and right work fine. What's the problem?