Dealing with Image Uploads

I need to figure out the best way from the backed the admin can upload images, the tricky part is the site has all different kinds of images (small product thumbs, large version, they want to be able to upload images into the jquery slider on the home page, images for a new sections, featured product on index page to name a few of the different sizes)

 

And there is no way to know if they are even going to upload the right dimensions for each type of image.

 

What is the best way to do this? I cannot seem to think of anything having a table for each_image how it relates to that page, that seems like the opposite of what should be done.

 

Any idea would be great.

 

Thanks, Dave