Ken, a couple of comments:
People interested in the human perception issues of color, might enjoy reading
the long popular article by Edwin Land (Polaroid fame), which appeared in
Scientific American.(Edwin H. Land, "The Retinex Theory of Color Vision,"
Scientific American, Vol. 237, No. 6, pp. 108-128, December 1977.)
His theory of color perception is termed "Retinex theory".
here are a few related simplified links:
http://people.msoe.edu/~taylor/eisl/land.htm
http://www.wendycarlos.com/colorvis/color.html
http://en.wikipedia.org/wiki/Color_constancy
http://www.wendycarlos.com/colorvis/retinex.html
http://color.psych.upenn.edu/brainard/papers/retinex.pdf
http://www.rowland.harvard.edu/organization/land/theory.php
One interesting thing is the brain can do a surprisingly good job of
reconstructing a full set of colors from a display screen, even if only 2 types
of carefully chosen color pixels are used, in place of 3.
There are so many variations on the more than tri-color camera sensor matrix,
which have been suggested and patented. A very interesting variation but for
color screen display use, is using RGBW. (W = white)
Some of the Fuji and other >3 color sensors land up with non-rectangular pixel
layout. This can mean the resolution is highest on a diagonal not horizontal
and vertical axis. This is a slight disadvantage apparently, as
we percieve better sharpness, if the resolution is highest on the horizontal.
A dificulty with the Foveon sensor, is not just their execution and having to
have a different dematrixing software/hardware, which is more expensive because
of lower volumes,but the RGB absorbtion curves have very broad overlap with one
another, making it much harder,to seperate the colors accurately. This tends to
magnify the noise despite the inherent advantage of not throwing away more than
2/3 of photons, as in the normal 2D filter sensor. Using another type of
vertical filter in a stackerd sensor, as you suggest, could theoretically
retain this photon (noise) advantage, if it were practical to make.
The human eye is similar to the Foveon sensor in that the absorbtion spectrum
of the different Rhodpsins in the eye are very similar, with huge overlap
making the brains job much tougher, in sorting out the real colors. This is an
example of why the eye is a rather imperfect, but highly optimised design,
despite what old creationists used to claim about godly design perfection in
the eye!
see curves here: http://www.wendycarlos.com/colorvis/conecurv.jpg
and discussion of opsins here : http://en.wikipedia.org/wiki/Rhodopsin
Tim Hughes
--- On Mon, 11/16/09, Ken Norton <ken@xxxxxxxxxxx> wrote:
> From: Ken Norton <ken@xxxxxxxxxxx>
> Subject: [OM] Pixel Wars - The Next Generation
> To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
> Date: Monday, November 16, 2009, 5:09 AM
> A shameless plug alert.
>
> We have a new article posted on Zone-10 which is predicting
> future
> development of sensors in our digital cameras. I'm sure a
> few things in it
> may seem a little futuristic, but isn't that the purpose of
> a prediction
> article? However, each and every technology mentioned in
> the article is
> found through patent searches and some slick detective
> work.
>
> http://zone-10.com/cmsm/index.php?option=com_content&task=view&id=461&Itemid=1
>
> <http://zone-10.com/cmsm/index.php?option=com_content&task=view&id=461&Itemid=1>
> AG
> --
> _________________________________________________________________
> Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
> Archives: http://lists.thomasclausen.net/mailman/private/olympus/
> Themed Olympus Photo Exhibition: http://www.tope.nl/
>
>
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|
