External Image Compression

We have users sharing links that are from External sources like Imgur.com. Most of the time these images are 4mbs+. Recently we have had a user do a few of these images which kills our site load time from 5 seconds to 20 seconds. If I remove those images it works fine. But these images make the page size increase drastically.

So how can we setup external compression or preview or something because this is killing my site and people are complaining

I've left the images there for now but I may ask the user to try and compress them and maybe upload them to our gallery vs imgur