Ion-scroll with large image across multiple screen sizes

I have a large image 2560x7150 that I am using in an ion-scroll. The idea is that the image height will always scale to fit the entire height whether portrait or landscape and that the user can only scroll horizontally. This same image can be used for various phone and tablet resolutions:

1024x768 iPad
2048x1563 iPad Retina
2560x1600 Android tablet
960x640 iPhone 4
1136x640 iPhone 5
1334x750 iPhone 6
2208x1242 iPhone 6 Plus
Android phone

I am not sure how to get the auto height scaling to work. Here is a starter CodePen:

Thanks for the help.