Andy: IRC is a text-based chat communications medium. It is not some uber duper hyper leet chat medium with super powers like MSN or AIM or any of the others.
Here's an idea, tell your friend to open the image with paint and resize it to 25% of the original size, save it, and send that to you.
Otherwise, don't accept images from just anyone.
IRC is a far older chat medium than AIM or MSN Messenger combined
Its 100% text based, which is why I like it.
IRC clients usually stick to the IRC RFC standards so everyone can interoperate correctly.
If you want it bad enough, find someone who will write a DLL for the function, then code a script to use sockets to send the file into a 'temporary cache', and open it in a picture window