There are a lot of video editing programs that can convert a DVD from one resolution to another–in this case, probably 480i to 720p. But all that does is average and smear the pixels to the higher pixel count, but it doesn't add any clarity to the image. Depending on the quality of the software, it might even degrade it.
I have two HD televisions, as well as the 4K computer monitor I'm staring at right now. In my experience, televisions and monitors with fixed resolution provide a higher quality picture when they're fed DVD video at its native resolution and do the upconverting themselves.