Dual monitor wallpaper question

Hello, I am running a dual monitor setup. My primary monitor is my laptop, 15.4 inches and the resolution is 1280x800 and my second lcd monitor is 17 inches and the resolution is 1280x1024. Well my question is how do I make both wallpapers fit to the screen. The primary screen is fit to the screen but not the second monitor. I have the stretch option enabled in the desktop features but it still doesn’t work. It looks annoying so that’s why I am asking.

Thanks in advance.