Abstract:
Using hexagonal grids to represent digital
images have been studied for more than 40 years.
Increased processing capabilities of graphic devices
and recent improvements in CCD technology have
made hexagonal sampling attractive for practical
applications and brought new interests on this
topic. The hexagonal structure is considered to be
preferable to the rectangular structure due to its
higher sampling efficiency, consistent connectivity
and higher angular resolution and is even proved
to be superior to square structure in many
applications. Since there is no mature hardware for
hexagonal-based image capture and display,
square to hexagonal image conversion has to be
done before hexagonal-based image processing.
Although hexagonal image representation and
storage has not yet come to a standard,
experiments based on existing hexagonal
coordinate systems have never ceased. In this
paper, we firstly introduced general reasons that
hexagonally sampled images are chosen for
research. Then, typical hexagonal coordinates and
addressing schemes, as well as hexagonal based
image processing and applications, are fully
reviewed.
