How to extract high resolution still pictures from dvd?

Greetings everyone

Im on a mission to make some High Quality still pictures from the dvd Lord of the rings. Somehow I cant find the wisdom how to make a finer still picture then a windows screenshot :frowning:

I would like to be able to do them as fine as possible, need to make a big picture for some kids.

Hope you can haelp me.

Use snapshot function in Nero Showtime if you have Nero

Or PowerDVD.