You need to change the setting from your Camera.
Change the in crop from the Framing Guide in your Camera.Turn off the in camera 16:9 framing guide.
You could also use Plug-ins for Adobe Photoshop Lightroom | Adobe Labs
Create a Tiff file in your Canon raw processing Software to recover the information.
Yes, I realize that, but I'm looking for a way to salvage the images I already have. I've tried loading the plug-in, but it won't load.