Urrggghhh, PHP? But this is exactly the kind of thing that PHP is good at. Dump a file in a directory that does one specific thing, and you're good to go. No n

Urrggghhh, PHP? But this is exactly the kind of thing that PHP is good at. Dump a file in a directory that does one specific thing, and you're good to go. No need to integrate it with the rest of your web site. It's just a little CGI-like script that does its own thing. But if you use this on a smallish VPS, keep an eye on memory usage. Image processing in PHP tends to hog a lot of RAM, and even a small number of simultaneous requests can crash a server. You might need to warm your cache a little bit before going public with new images.