Making a pattern from clothes

So I have this dress, It looks very similar to the dress I'm trying to create in This Post But I LOVE this dress, and I would not like to cut it up just to get the pattern, anyone have any suggestions?

I've posted a link to a pattern that will suit the top half (that's free).

I guess you can recreate the pattern without taking it apart. Maybe put it on a dummy (or a friend) and pin large bits of material to it (taking note of the seams and any darts). Mark up the scrap material and then you have your pattern pieces (just without a seam allowance). Make sense?