WinDVD Screencap Size

I have Intervideo WinDVD 5 Platinum, and I checked the memories but didn't seem to find the answer to my question.

When I cap things, they are at a resolution of 852x480. Is there any way I can change (directly through WinDVD) the size of the screencaps? I need them bigger, as I'm trying to make some wallpapers.

Thanks!