Some image related nodes :
Get Image Height : Retrieves the height of an image in Vuo coordinates (not pixels) corresponding to a width of 2 (height is 2 if the image is a square, 1 if it's half the width etc).
Get Image Ratio : Retrieves the ratio of an image, similar to retrieving the image height and width, and calculating width / height.
Put these .c nodes in your Vuo Modules folder.
You can search for these nodes by typing
BSS in your node library.
Public Domain. Any feedback or improvements welcome.