If it's of any help, we store our images by sku eg. 124589763.jpg in a one to many table, one product can have many images so it goes sku 124589763-1.jpg 124589763-2.jpg.
We have over 40,000 images on a cdn, when we create a new product, we store the images on our local machine, when an new image is added, we have software called goodsync than senses the change in the local folder and uploads the images into the same file structure on gogrid cdn.
The new product is launched on our websites and all the images are available for distribution everywhere.
Works for us