Code crashing page

My project here, which is to try to implement a median blur filter for an image, is not working. It works for small costumes, but on a full sized image, google gives me a "page unresponsive" error. Are images just to big to handle, or can I change my code to make it work? Thanks!

Did you mean to post a link?

Oops. :blush: Here you go.

You should say clear what do you want us to help you.

Oops, nobody ever answered this. Sorry!

But the script fails for me right away because there's no costume named IMG_whatever it was.