I think I'm probably overlooking the simple answer, but I've googled the hell out of this and I just don't know.
I want to write a script that will track the hits to a specific image, which will be called to a page on another server, and save the hit information to a mysql database. The only part I can't figure out is how to tell php to track the image. Help? Hints?

eta: Thanks to all, I figured out and implemented a solution that works great so far. zimzat put me on the right track.