I used WinDVD 6 to capture files from the DVD, and Elecard Mpeg2 player to capture from the HD stream. Both were captured directly to BMP files and converted to JPG at very high quality so there should be almost no artifacting introduced (sorry, the BMP files were too large to use).
I used Photoshop to bicubically resample the DVD source images from 852x480 to match the 1920x1080 of the HD images. This page features the HD image sampled down to the DVD's resolution of 852x480. Surprisingly, even at DVD-resolution the HD source features more detail.
Mouseover any of the images here to see the HD downsample. You can see the full-size comparisons by clicking on the images on this page. The difference is pretty amazing.
I tried to capture identical frames on both sources, but I missed by a frame or two on some of these.