I think you must have viewed this just as I was fixing the '-' typo in the href tag (mozilla seems to be having issues with cutting and pasting, so I typed the code out directly into the text field and missed the typo the first time around.)

I like your suggestion about the Image::Size module, I hadn't heard of it before but I'll definately check it out now. I'll also add on the /i to ignore case as you suggested. Thanks again for the comments :)

Update: the script now uses the Image::Size module as suggested by dws. Thanks again to everyone for the comments :).