HTTPS in all IMG tag links?

[DCD.RB]

Sorry, not sure if I'm entirely clear on this.

I only see search & replace query.

What I'm trying to do is when someone posts the code:
[ img ] http://image.com/image.jpg [ /i mg ]

It will automatically transform into an HTTPS link. I'm not concerned about the image being broken here, because the user should notice/realize immediately after when it doesn't properly display.

And for the most part, it seems 90%+ of the image hosts our users use does support HTTPS. They're just pasting in HTTP links, and adding the S has been a manual process I'd like to turn automatic if possible.