It is indeed The Arnolfini Marriage by Jan Van Eyck. It is one of the most famous paintings in the world, and is actually held in the National Gallery in London. However, you can see the detail far better in reproductions.
It is a really interesting picture, because it is full of symbolism. The couple are possibly the least interesting part of the picture.
It is also interesting because lots of the things that art historians thought that they knew about the picture where changed when the original deeds to the home of the couple were found in the chimney of their house. (which was a common place to keep them)