Good point ...
If the pic already exists on your hard disk and you're using a Windows PC comouter, this is the best program I've found and let's you re-size for "large" screen sizing if you want.
Microsoft's FREE Image Resizer (click here)
This FREE PowerToy enables you to resize one or many image files with a simple right-click of your mouse
........ click on the link above and install it on your system.
Regards,
Badger