  The realization that direct imaging of extrasolar planets could be
technologically feasible within the next decade or so has inspired a great deal
of recent research into high-contrast imaging. We ourselves have contributed
several design ideas, all of which can be described as shaped pupil
coronagraphs. In this paper, we offer a complete and unified survey of
asymmetric shaped pupils designs, some of which have been published in our
previous papers. We also introduce a promising new design, which we call
barcode masks. These masks achieve the required contrast with a fairly large
discovery zone and throughput but most importantly they are perhaps the easiest
to manufacture and might therefore stand up best to a refined analysis based on
vector propogation techniques.
