How to keep images on DVD from being copied

I am a freelance portrait/wedding photographer. I am using NeroVision Express 3 to burn DVD's of the images I've done on photo shoots of clients. I am trying to find a way to copy protect those images so they cannot be copied to a computer or printed from the DVD, as my images are the product I sell. I have been asked about making DVD's with background music of their images, and I've got that part figured out, but how to I protect my images from being downloaded from the DVD without putting a watermark across them that can be seen when viewing the DVD?!? Everything I've searched for online seems to be for either web images or how to burn protected DVD's. Any ideas would be so appreciated!

WVAngel