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Guest
Posted: Wed Apr 02, 2008 3:11 pm
How does color vision really work?

We all know about the standard theory of color vision -- that there
are three kinds of cones in the human eye partitioning the world of
colors into three dimensions. Researchers have even found evidence
for multiple pigments through molecular genetics.

But does this really explain how color vision works? There is a great
deal about color vision about which the standard theory says nothing
or indeed says the wrong thing. Consider the following:

The standard theory can not explain the subjective color phenomenon
where spectrally ordered colors are induced with only time-modulated
black and white illumination as in the well-known Benham's Top.

Multiple pigments have been found within the same cone. This makes no
sense in the standard three cone model.

The color violet looks very much like purple, a mixture of red and
blue. The standard model fails to explain this basic fact of color
vision.

Using adaptive optics techniques it has been possible to stimulate a
single cone in the living eye. Instead of either a red or green or
blue sensation when such a single cone is stimulated (as required by
the three-cone theory) subjects report seeing virtually any color of
the spectrum, even white, regardless of the color of the illuminating
light.

Why do cones have a cone shape? To date no one has offered an
explanation of the absolute dichotomy in shape between the rods that
provide black and white night vision and the cones that provide color
vision in daylight. Are they different is shape just so we can tell
them apart?!

And what about color blindness? It has long been debated whether the
common forms of color deficit vision are due to missing "red" or
"green" cones or whether the pigments got mixed up so that, say both
"red" and "green" cones have the same green pigment. In fact,
experimental evidence exists contradicting both "explanations".

The standard model of human color vision is inherently a static
model. It utterly fails to explain many of the dynamic aspects of
color vision, including the "resolution of mixed colors".

An accounting of these and many other mysteries of color vision is
offered by a new, comprehensive model of color vision - the cone
spectrometer model. The model is based on fundamental dielectric
waveguide propagation effects in a tapered fiber - cones. It directly
explains all of the common phenomena of color vision as well as a
number of what have hitherto been profoundly puzzling and enigmatic
aspects of color. It also suggests a new understanding of the common
forms of color deficit vision and a new approach to possible clinical
treatments.

The details of the difficulties with the standard model and how the
cone spectrometer model resolves all these issues can be found on the
website:

http://ConesAndColor.net
J. B. Wood
Posted: Thu Apr 03, 2008 2:47 am
Guest
In article
<31408f36-08f0-4c6c-9762-14bd34473dd3@a22g2000hsc.googlegroups.com>,
drjoaom@gmail.com wrote:

Quote:
How does color vision really work?

We all know about the standard theory of color vision -- that there
are three kinds of cones in the human eye partitioning the world of
colors into three dimensions. Researchers have even found evidence
for multiple pigments through molecular genetics. <snip


Hello, and I would direct you to read the published papers (check
Scientific American archives) of Edwin Land and his groundbreaking work in
this area. How the eye/brain discerns color is not as simple as high
school physics books would have us believe. Land also demonstrated how a
color picture can be reconstructed using two slide projectors each having
a monochromatic slide. Sounds far-fetched but it does work and
underscores the complexity of color interpretation. Sincerely,

John Wood (Code 5550) e-mail: wood@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337
Douglas Eagleson
Posted: Fri Apr 04, 2008 9:44 am
Guest
On Apr 2, 6:11pm, drjo...@gmail.com wrote:
Quote:
How does color vision really work?

We all know about the standard theory of color vision -- that there
are three kinds of cones in the human eye partitioning the world of
colors into three dimensions. Researchers have even found evidence
for multiple pigments through molecular genetics.

But does this really explain how color vision works? There is a great
deal about color vision about which the standard theory says nothing
or indeed says the wrong thing. Consider the following:

The standard theory can not explain the subjective color phenomenon
where spectrally ordered colors are induced with only time-modulated
black and white illumination as in the well-known Benham's Top.

Multiple pigments have been found within the same cone. This makes no
sense in the standard three cone model.

The color violet looks very much like purple, a mixture of red and
blue. The standard model fails to explain this basic fact of color
vision.

Using adaptive optics techniques it has been possible to stimulate a
single cone in the living eye. Instead of either a red or green or
blue sensation when such a single cone is stimulated (as required by
the three-cone theory) subjects report seeing virtually any color of
the spectrum, even white, regardless of the color of the illuminating
light.

Why do cones have a cone shape? To date no one has offered an
explanation of the absolute dichotomy in shape between the rods that
provide black and white night vision and the cones that provide color
vision in daylight. Are they different is shape just so we can tell
them apart?!

And what about color blindness? It has long been debated whether the
common forms of color deficit vision are due to missing "red" or
"green" cones or whether the pigments got mixed up so that, say both
"red" and "green" cones have the same green pigment. In fact,
experimental evidence exists contradicting both "explanations".

The standard model of human color vision is inherently a static
model. It utterly fails to explain many of the dynamic aspects of
color vision, including the "resolution of mixed colors".

An accounting of these and many other mysteries of color vision is
offered by a new, comprehensive model of color vision - the cone
spectrometer model. The model is based on fundamental dielectric
waveguide propagation effects in a tapered fiber - cones. It directly
explains all of the common phenomena of color vision as well as a
number of what have hitherto been profoundly puzzling and enigmatic
aspects of color. It also suggests a new understanding of the common
forms of color deficit vision and a new approach to possible clinical
treatments.

The details of the difficulties with the standard model and how the
cone spectrometer model resolves all these issues can be found on the
website:

http://ConesAndColor.net

Sense as spectra would cause cogition of the fact. Sense of spectra
as a cell would entail a fairly sophisticated cell structure.

It does not function as a particle or quanta energy detector was the
issue. How does it function?

What possible cell structure can cause a nerve signal maybe
proportional to spectra? So depth as spectra was the likely cause to
signal. A tissue formed a depth detector. So the spectra was a ,
(blue-deep)(red-near surface).

We see a portion of the colors. No more and no less as a detector was
the cone.

Signal construction was the next issue and to generate a model of the
color sense was a famous physicists discovery. I forgot his name, but
I took a class with him. A two valued signal would cause the a sensed
color in the mind. Now this is tricky cognition modeling just to make
perspective. The two values add and a color would be the output as a
model. A rod senses a cone detects color. Two cell bodys add. Why
were these to occur like this? This was his hint at true correct
theory of cognition of color.

Signal was the issue a depth signal was only a relative signal while
the rod was absolute white spectra "designed". The sensitivity to
white light was perfect single constant nerve stimulation. signal
level is proportional to white balanced intensity for the rod!

Here comes the genius work:

A
|
|*****************************
|
|
|
|
|
_______________________
frequency

* the light spectra as output assumes a white balanced rod.

B
|
|*
| *
|
| *
|
| *
|
| *
__________________________
frequency
* a cone's signal response is listed.

A+B = constant

A-signal rod
B-signal cone

The a priori of white spectra for the rod allowed a single variation
to exist. Understand how response curves add. A priori was built
in. We see the intended spectra.

A color a priori would cause the signal to be(Red= b,green=b+a,blue=b
+a^2)

A differential design allows all color to be a single valued system.
Douglas Eagleson
Posted: Fri Apr 04, 2008 9:44 am
Guest
On Apr 3, 5:47am, w...@itd.nrl.navy.mil (J. B. Wood) wrote:
Quote:
In article
31408f36-08f0-4c6c-9762-14bd34473...@a22g2000hsc.googlegroups.com>,

drjo...@gmail.com wrote:
How does color vision really work?

We all know about the standard theory of color vision -- that there
are three kinds of cones in the human eye partitioning the world of
colors into three dimensions. Researchers have even found evidence
for multiple pigments through molecular genetics. <snip

Hello, and I would direct you to read the published papers (check
Scientific American archives) of Edwin Land and his groundbreaking work in
this area. How the eye/brain discerns color is not as simple as high
school physics books would have us believe. Land also demonstrated how a
color picture can be reconstructed using two slide projectors each having
a monochromatic slide. Sounds far-fetched but it does work and
underscores the complexity of color interpretation. Sincerely,

John Wood (Code 5550) e-mail: w...@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

The two valued system was found to exist. I took a class with Prof.
Roger Mcleod at UMASS Lowell once. He actually differentially stated a
two value to color. Call him if you have an intense interest in color
perception.
J. J. Lodder
Posted: Fri Apr 04, 2008 9:44 am
Guest
<drjoaom@gmail.com> wrote:

Quote:
How does color vision really work?

Always more complicated that you could have imagined.

Quote:
We all know about the standard theory of color vision -- that there
are three kinds of cones in the human eye partitioning the world of
colors into three dimensions. Researchers have even found evidence
for multiple pigments through molecular genetics.

That is not 'the standard theory', just a particular simplistic model.
It compares the eye to an analog camera.

Quote:
But does this really explain how color vision works? There is a great
deal about color vision about which the standard theory says nothing
or indeed says the wrong thing. Consider the following:

The standard theory can not explain the subjective color phenomenon
where spectrally ordered colors are induced with only time-modulated
black and white illumination as in the well-known Benham's Top.

At the next level of sophistication you can compare the eye
to a digital camera with 'automatic white balance'
For human vision the phenomenon is known as 'colour constancy'
Perceived colours of objects are to a large extent
independent of the colour temperature of the light falling on them.

However, the human eye/brain is far more sophisticated still.
There is 'postprocessing' going on at several more levels
to extract as much information as possible from the image.
This often fails in subtle ways,
as demonstrated by an immense variety of optical illusions.

Quote:
Multiple pigments have been found within the same cone. This makes no
sense in the standard three cone model.

The color violet looks very much like purple, a mixture of red and
blue. The standard model fails to explain this basic fact of color
vision.

It does when you look at the actual absorbtion spectra of the cones.

[snippage]

It seems to me (if I may say so)
that you are not really interested
in what is known about colour vision.
You are harping on (mmostly imagined)
shortcomings of what is known about human vision
to promote your own (may I say 'pet'?) theory,

Jan
Tom Roberts
Posted: Fri Apr 04, 2008 9:44 am
Guest
J. B. Wood wrote:
Quote:
Hello, and I would direct you to read the published papers (check
Scientific American archives) of Edwin Land and his groundbreaking work in
this area. How the eye/brain discerns color is not as simple as high
school physics books would have us believe. Land also demonstrated how a
color picture can be reconstructed using two slide projectors each having
a monochromatic slide. Sounds far-fetched but it does work and
underscores the complexity of color interpretation.

Yes. He gave a colloquium at Bell Labs many years ago (and surely many
other places, as he brought his own equipment). It was quite striking
when he used two projectors to display a black-and-white and a
black-and-red image of a scene -- it was red and white until he
carefully adjusted them to be precisely aligned, and it suddenly
"jumped" into full color!

While I remember that quite vividly, this is less well remembered: I
believe this is due to the non-monochromatic response of the red pigment
in the human eye -- it has a broad maximum in the red, a broad minimum
in the green, but another broad maximum in the blue. The brain has
learned this and accounts for it in the sorts of scenes it was trained
on. But in his demonstration (and in Polaroid pictures in general) the
brain is fooled and regenerates a full color scene. There is A LOT more
going on than just the spectral response of eye pigments.

Tom Roberts
Guest
Posted: Mon Apr 07, 2008 10:44 am
Color vision is quite a complicated topic. The great philosopher
and author Goethe advanced a theory (in "Zur Farbenlehre") meant
to compete with Young's recently formulated trichromatic theory.
Goethe's theory has been proven wrong in most respects, because
it was based on sensations and color names rather than on
physical stimuli.

The problem is the same with any human sense: The sensations
must be described in physical terms before any useful progress
can be made. The confusion of sensations with physics is
shared by a genius, Goethe, so the originator of this thread really
shouldn't feel very bad about it.

Think of hearing, for an analogy: One can actually hear a sound,
and measure the sound to determine why one is hearing (whatever).
But, if one has "ringing" in the ears after a loud noise, the ringing
has no physical basis outside the body. Confusing ringing with real
sounds makes hearing complicated and mysterious. Ignoring
sensations and dealing with measurable responses separates
fact from fancy.

The trichromatic theory ONLY works for real light and measured
responses. It fails when applied to false sensations or confusing,
subjective reports.

The same way, the judicial system fails when applied in a work of
fiction such as the "Blade" movies or the Adventures of Robin Hood.

Don't expect science to succeed in subjectivity or fiction.

J. J. Lodder wrote:
Quote:
drjoaom@gmail.com> wrote:

How does color vision really work?

Always more complicated that you could have imagined.

We all know about the standard theory of color vision -- that there
are three kinds of cones in the human eye partitioning the world of
colors into three dimensions. Researchers have even found evidence
for multiple pigments through molecular genetics.

That is not 'the standard theory', just a particular simplistic model.
It compares the eye to an analog camera.

But does this really explain how color vision works? There is a great
deal about color vision about which the standard theory says nothing
or indeed says the wrong thing. Consider the following:

The standard theory can not explain the subjective color phenomenon
where spectrally ordered colors are induced with only time-modulated
black and white illumination as in the well-known Benham's Top.

At the next level of sophistication you can compare the eye
to a digital camera with 'automatic white balance'
For human vision the phenomenon is known as 'colour constancy'
Perceived colours of objects are to a large extent
independent of the colour temperature of the light falling on them.

However, the human eye/brain is far more sophisticated still.
There is 'postprocessing' going on at several more levels
to extract as much information as possible from the image.
This often fails in subtle ways,
as demonstrated by an immense variety of optical illusions.

Multiple pigments have been found within the same cone. This makes no
sense in the standard three cone model.

The color violet looks very much like purple, a mixture of red and
blue. The standard model fails to explain this basic fact of color
vision.

It does when you look at the actual absorbtion spectra of the cones.

[snippage]

http://ConesAndColor.net

It seems to me (if I may say so)
that you are not really interested
in what is known about colour vision.
You are harping on (mmostly imagined)
shortcomings of what is known about human vision
to promote your own (may I say 'pet'?) theory,

Jan
J. J. Lodder
Posted: Tue Apr 08, 2008 9:34 am
Guest
<JmmWill@yahoo.com> wrote:
[snip out of context top-posting]

A point of order, if moderators permit for once.

Please do not top-post, and I may reply,
if you also reply in an orderly fashion
to the points I raised,
instead of posting another monologue.

Furthermore, PLEASE do not throw away the References header,
thereby destroying the thread structure.
This way I don't even see from the thread
that you were replying to something I wrote.

[ Mod. note: To be fair, references are likely to have been truncated
somewhere other than at the poster's end. -ik ]

Best,

Jan

--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet?
 
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