There are a number of applications which benefit
from high resolution displays, for example,
immersive virtual reality and scientific
visualization. Unfortunately projector
technology is currently limited to around the
XGA or SXGA pixel resolution and they are still
rather expensive. The approach that can be taken
then is to use low cast commodity projectors and
tile a number of them together, each driven by
either a different computer or a different
graphics pipe on the same computer.
The first thing one discovers with commodity
projectors is that, unlike the more expensive
models, they don't have inbuilt support for
tiled displays. In addition their optics is such
that it isn't possible to reliably align
multiple projectors in a pixel perfect way (or
even close). With the tiling not being pixel
perfect one ends up with either a gap between
the images or a double bright seam, both are
quite objectionable especially so for content
where the camera is panning or objects are
moving across the seam. The solution is to
overlap the two images by a significant amount
and modify the pixels in the overlap region so
as to make the overlap as invisible as possible.
The reason why this works is that now any slight
projector misalignment or lens aberration only
reveals itself as a slight blurring of the image
and not as a sharp seam or gap.
Challenge:
When projected images overlap, there is a region
of elevated brightness where the intensity must
be toned down. Our advanced algorithms calculate
the precise values required to fade the pixels
as they transition from one projector to the
next.
The process of edge blending involves
manipulation of individual pixels to ensure
perfect intensity in the blend zone. The process
involves precise algorithms which measure
intensity of the projectors and then fad from
full intensity to zero over a specified blend
zone. The result is a perfect seamless display.
Why
Edge blending:
Creating very high resolution display
Any aspect ratio (exp. 5:1 instead of
4:3 or 16:9)
Multiple, smaller, less-expensive
projectors can be used
