I am not asking about regular "execute php on my domain and get URL" but this:
I display image from php, here: http://myservice.com/ShowImage.php?Id=10
So Bobby who runs a website BobbyBlog.net could use this image on his blog like:
<img src=http://myservice.com/ShowImage.php?Id=10>
I want to know that Bobby has loaded image on his website, so what I need to intercept in my ShowImage.php script would be "BobbyBlog.net" string. I am afraid this is not possible with PHP as image request is separated from Bobby blog. What do you think?