Stretch an image?

I've been asked to write a script that uploads an image and resizes it to 300x100 (regardless of the original dimensions). They don't want it to be a scaled version of the original. They want 300x100 no matter what. Yes, I understand that's pretty silly, but it is what it is. So, I figure it has something to do with imagecopyresampled. However, when I use that function, it shrinks it to a proportionately sized image (it will never be wider or taller than 300x100... but often it shrinks to something like 100x100 or 120x100. Any suggestions?