I am not sure if I DO have any images ranked but I think I know a couple of ways to do so.
The name of the image must be what it is...i.e if it's an image of a place in the US...the image should be named after that unlike what most people do and just type in some odd words..
Also, while placing the images in HTML...you should always add the alt attribute to it
It helps alot.
i.e
Hope it helps
