I'm creating a site with an extensive product catologe, and I thought it would be more efficient, and ultimately easier to have one image for each product, and use PHP to dynamically resize them for display. I would potentially have three different image sizes, a thumbnail, a medium-sized display image, and a larger detail image.

I've looked online for some scripts, but the majority seem to create a new image which is actually saved on the sever, instead of simply resizing the image.

Any suggestions?