X3: Why Greenx2=Resolutionx2? Wowx3 Images?

[Jung Lee]

Re: Foveon X3: Why Greenx2=Resolutionx2? Wowx3 Images?

Question 1. Why does Resolution depend on Green?
According to FOVEON: http://www.foveon.net/X3_comparison.html

"As you can see, the camera equipped with Foveon X3 technology takes sharper pictures. Twice as sharp, to be precise. That 's because it captures twice as much green as the camera with the mosaic capture system, and the green wavelengths of light are critical in defining image detail."

Question 2. Why these 3 1.3 MB JPEG images have the BEST COLOR AND RESOLUTION THAT I HAVE SEEN TO DATE? Technical Reasons?
http://www.foveon.net/img/Pressroom/Boxer.jpg
http://www.foveon.net/img/Pressroom/Cat.jpg
http://www.foveon.net/img/Pressroom/PoolTable.jpg

Best Regards.
Jung Lee
Pixedx3!

 

[Igor R.]

Re: Foveon X3: Why Greenx2=Resolutionx2? Wowx3 Images?
Question 1. Why does Resolution depend on Green?

Cuz:
1 We have 50% of green sensors in our eyes, and 25% of reds and blues each.

2 Our green sensors are working under low light conditions, so green light is more important for our eyes, and more green is accepted as normal by our video-procesor (in brain). Have you seen "The Matrix"? Lets say, green light for us (people) is like B&W, ye, maybe it is difficult to understand, or maybe I found bad examples for explanations, I guess oculists will explain you better (I'm serious!).

 

[excal]

I guess it stems back to predators and green foliage in the Darwin'ian evolution? No?

Re: Foveon X3: Why Greenx2=Resolutionx2? Wowx3 Images?
Question 1. Why does Resolution depend on Green?

Cuz:
1 We have 50% of green sensors in our eyes, and 25% of reds and
blues each.
2 Our green sensors are working under low light conditions, so
green light is more important for our eyes, and more green is
accepted as normal by our video-procesor (in brain). Have you seen
"The Matrix"? Lets say, green light for us (people) is like B&W,
ye, maybe it is difficult to understand, or maybe I found bad
examples for explanations, I guess oculists will explain you better
(I'm serious!).

--Excal

 

[Jung Lee]

Dear Igor and Excal:

Many thanks for your prompt responses!

Nightvision X3 gogles for the desert lizards!

Superexcalifragilisticexpigorlidelicious ideas!

Muchos Gracias! Hombres Sinceros!

Best Regards,

Jung Lee
1pix3

 

[Mark Grebner]

Question 1. Why does Resolution depend on Green?
According to FOVEON: http://www.foveon.net/X3_comparison.html
"As you can see, the camera equipped with Foveon X3 technology
takes sharper pictures. Twice as sharp, to be precise. That 's
because it captures twice as much green as the camera with the
mosaic capture system, and the green wavelengths of light are
critical in defining image detail."

Gibberish! Green is important to resolution because it's in the middle (roughly) of the spectrum of light visible to humans. The blue and red info is used mainly to provide chroma values, while the green carries most of the luminance. The fact X3 has "twice as much green" is pretty meaningless. "Twice as much" as Tide detergent?

Conventional consumer digicams devote 50% of their sensors to green, so if the X3 can read green at every site, it would have twice as many sensors. How does that create a picture "twice as sharp"? Is sharpness a one-dimensional quality or two-dimensional? What other design constraints are affected by the new technology?

It sounds interesting, but the press materials are somewhere between misleading and unintelligible.

 

[Jung Lee]

Hey, let's have second, third and more opinions?
Is there a Optical Doctor in DPR house?
Specializing In Green Lizzy Aliens?
Straight from X3 Files?
Regards,
JL
Roses are Read...
Digital dogs are Blue...
Not sweet as greenX2!

 

[warren prasek]

...i...think.. they are trying to simplify a very complex issue so we ignorant dolts can attempt to successfully absorb and comprehend it... fat chance!

Question 1. Why does Resolution depend on Green?
According to FOVEON: http://www.foveon.net/X3_comparison.html
"As you can see, the camera equipped with Foveon X3 technology
takes sharper pictures. Twice as sharp, to be precise. That 's
because it captures twice as much green as the camera with the
mosaic capture system, and the green wavelengths of light are
critical in defining image detail."

Gibberish! Green is important to resolution because it's in the
middle (roughly) of the spectrum of light visible to humans. The
blue and red info is used mainly to provide chroma values, while
the green carries most of the luminance. The fact X3 has "twice
as much green" is pretty meaningless. "Twice as much" as Tide
detergent?

Conventional consumer digicams devote 50% of their sensors to
green, so if the X3 can read green at every site, it would have
twice as many sensors. How does that create a picture "twice as
sharp"? Is sharpness a one-dimensional quality or two-dimensional?
What other design constraints are affected by the new technology?

It sounds interesting, but the press materials are somewhere
between misleading and unintelligible.

--------------------------------------i was gonna type something witty here but then i changed my mind.

 

[Jung Lee]

Dear Igor: What about this?

Current understanding is that the 6 to 7 million cones can be divided into "red" cones (64%), "green" cones (32%), and "blue" cones (2%) based on measured response curves. They provide the eye's color sensitivity. The green and red cones are concentrated in the fovea centralis . The "blue" cones have the highest sensitivity and are mostly found outside the fovea, leading to some distinctions in the eye's blue perception.

The "blue" cones are identified by the peak of their light response curve at about 445 nm. They are unique among the cones in that they constitute only about 2% of the total number and are found outside the fovea centralis where the green and red cones are concentrated. Although they are much more light sensitive than the green and red cones, it is not enough to overcome their disadvantage in numbers. However, the blue sensitivity of our final visual perception is comparable to that of red and green, suggesting that there is a somewhat selective "blue amplifier" somewhere in the visual processing in the brain.

The visual perception of intensely blue objects is less distinct than the perception of objects of red and green. This reduced acuity is attributed to two effects. First, the blue cones are outside the fovea, where the close-packed cones give the greatest resolution. All of our most distinct vision comes from focusing the light on the fovea. Second, the refractive index for blue light is enough different from red and green that when they are in focus, the blue is slightly out of focus (chromatic aberration). For an "off the wall" example of this defocusing effect on blue light, try viewing a hologram with a mercury vapor lamp. You will get three images with the dominant green, orange and blue lines of mercury, but the blue image looks less focused than the other two.

Reference: http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html

Igor Radionoff wrote:
Cuz:

1 We have 50% of green sensors in our eyes, and 25% of reds and
blues each.
2 Our green sensors are working under low light conditions, so
green light is more important for our eyes, and more green is
accepted as normal by our video-procesor (in brain). Have you seen
"The Matrix"? Lets say, green light for us (people) is like B&W,
ye, maybe it is difficult to understand, or maybe I found bad
examples for explanations, I guess oculists will explain you better
(I'm serious!).

 

[KenEis]

The human eye is most sensitive to green and chrolophyle is green because the suns stongest output is in the green wavelengths. I know the sun looks yellow but the color temperature of the suns surface is green. So that where we have the most sensitivity. Put another way the typical human can detect more subtle changes in green then in the red or blue wavelengths.

Re: Foveon X3: Why Greenx2=Resolutionx2? Wowx3 Images?
Question 1. Why does Resolution depend on Green?

Cuz:
1 We have 50% of green sensors in our eyes, and 25% of reds and
blues each.
2 Our green sensors are working under low light conditions, so
green light is more important for our eyes, and more green is
accepted as normal by our video-procesor (in brain). Have you seen
"The Matrix"? Lets say, green light for us (people) is like B&W,
ye, maybe it is difficult to understand, or maybe I found bad
examples for explanations, I guess oculists will explain you better
(I'm serious!).

--
Excal

 

[bronson]

Maybe a dumb question, but would is this true?

 

[Igor R.]

Maybe a dumb question, but would is this true?

Ye, it is, but there are 3 onecolor pixels needed to create one anycolor pixel. Hope, you know, what I'm talking about!

 

[synp]

Unlike modern camera lenses, the human eye is not apochromatic. That means that when you focus your eyes on a certain point, you can have the red light, the green light or the blue light in focus, but not all three at the same time.

Humans tend to focus on the green light. That way the red light is almost in focus, but the blue light is not. Since the green light is in sharpest focus, the brain uses the green image to detect objects and detail, while the blue light is only used for color casts. That's pretty good in nature because most details are green or red, not blue. This is also why orange-tinted glasses (that filter out blue) are used to improve night vision.

Because of this property of the eye, the Bayer mosaic has twice as much green as other colors. The X3 has real green detail in every pixel so the image may look more detailed to us.

Re: Foveon X3: Why Greenx2=Resolutionx2? Wowx3 Images?

Question 1. Why does Resolution depend on Green?
According to FOVEON: http://www.foveon.net/X3_comparison.html
"As you can see, the camera equipped with Foveon X3 technology
takes sharper pictures. Twice as sharp, to be precise. That 's
because it captures twice as much green as the camera with the
mosaic capture system, and the green wavelengths of light are
critical in defining image detail."

Question 2. Why these 3 1.3 MB JPEG images have the BEST COLOR AND
RESOLUTION THAT I HAVE SEEN TO DATE? Technical Reasons?
http://www.foveon.net/img/Pressroom/Boxer.jpg
http://www.foveon.net/img/Pressroom/Cat.jpg
http://www.foveon.net/img/Pressroom/PoolTable.jpg

Best Regards.
Jung Lee
Pixedx3!

 

[LokTo]

Something is green because it reflects green...

The human eye is most sensitive to green and chrolophyle is green
because the suns stongest output is in the green wavelengths. I
know the sun looks yellow but the color temperature of the suns
surface is green. So that where we have the most sensitivity. Put
another way the typical human can detect more subtle changes in
green then in the red or blue wavelengths.

--It's all about LUCK!.......LokTo http://seelokto.cjb.net/

 

[Fabio Amodeo]

I can't tell why, but the green channel of my TIFFs has most of the detail information, while blue has all the noise. When I mix channels to make a monochrome, green is the major source (still don't know why, I was simply taught to do so.Tutorials don't explain too much). The Foveon information about green must have to do with all this, although I will never be able to tell why.
Fabio

 

[Leon Wittwer]

Mark, Twice as much resolution is about right if you define resolution as the total number of effective image pixels. Assume we have two ccd with the same number of ccd cells. The first gets red, green, and blue measurements from each cell and the second has the Bayer pattern with half of the ccd cells being green. The resolving power (defined as how close can two points be resolved) is mainly determined by the green signals as the green has most of the luminance and detail. In the first case the nearest neighbor green is one pixel dimension away. In the second, the nearest neighbor green is 1.414 pixel dimension away. Thus the first ccd can resolve two points that are 0.707 closer than the second. Now how many pixels must the second have (in the same physical size ccd chip) to get the same resolving power. It must have about twice as many to get the nearest neighbor distance down. Thus the comment that the Fovean ccd has twice the resolution in the sense that you would have to put twice the number of ccd cells (Bayer pattern) in the same size ccd to get the approximately the same resolving power as the Fovean ccd. Hope that illuminates the issue.

 

[Jack40001]

This is very clear!
Jake.

Re: Foveon X3: Why Greenx2=Resolutionx2? Wowx3 Images?
Question 1. Why does Resolution depend on Green?

Cuz:
1 We have 50% of green sensors in our eyes, and 25% of reds and
blues each.
2 Our green sensors are working under low light conditions, so
green light is more important for our eyes, and more green is
accepted as normal by our video-procesor (in brain). Have you seen
"The Matrix"? Lets say, green light for us (people) is like B&W,
ye, maybe it is difficult to understand, or maybe I found bad
examples for explanations, I guess oculists will explain you better
(I'm serious!).

--Jake.

 

[Mark Grebner]

. . . Twice as much resolution is about right if you define
resolution as the total number of effective image pixels. Assume
we have two ccd with the same number of ccd cells. The first gets
red, green, and blue measurements from each cell and the second has
the Bayer pattern with half of the ccd cells being green. The
resolving power (defined as how close can two points be resolved)
is mainly determined by the green signals as the green has most of
the luminance and detail. In the first case the nearest neighbor
green is one pixel dimension away. In the second, the nearest
neighbor green is 1.414 pixel dimension away. Thus the first ccd
can resolve two points that are 0.707 closer than the second. Now
how many pixels must the second have (in the same physical size ccd
chip) to get the same resolving power. It must have about twice as
many to get the nearest neighbor distance down. Thus the comment
that the Fovean ccd has twice the resolution in the sense that you
would have to put twice the number of ccd cells (Bayer pattern) in
the same size ccd to get the approximately the same resolving power
as the Fovean ccd.

That was actually my point. It doesn't have "twice" the resolution, it has - maybe - 1.4 times the resolution. The measured result may not be exactly 1/sqrt(2), because no individual sensor data is available from the Bayer array, only merged results from groups of 2x2 pixels. Doubling the number of green pixels and using their individual values may not be exactly the same as (for example) doubling the sensor count of a Bayer CCD. But the final result is likely to be an increase in the number of resolveable line pairs by a factor of about 1.4.

 

[Jung Lee]

Dear Mark

I completely agree with you.

Color fidelity does reflect on perceived resolution.
Acid test would be depiction of White and shades of grey.
Something like muddy greys on color printer combining 3 colors for black.

Unless we again depend for the final image on superior interpolations and algoriths!

Regards,
Jung Lee

That was actually my point. It doesn't have "twice" the
resolution, it has - maybe - 1.4 times the resolution. The
measured result may not be exactly 1/sqrt(2), because no individual
sensor data is available from the Bayer array, only merged results
from groups of 2x2 pixels. Doubling the number of green pixels and
using their individual values may not be exactly the same as (for
example) doubling the sensor count of a Bayer CCD. But the final
result is likely to be an increase in the number of resolveable
line pairs by a factor of about 1.4.

. . . Twice as much resolution is about right if you define
resolution as the total number of effective image pixels. Assume
we have two ccd with the same number of ccd cells. The first gets
red, green, and blue measurements from each cell and the second has
the Bayer pattern with half of the ccd cells being green. The
resolving power (defined as how close can two points be resolved)
is mainly determined by the green signals as the green has most of
the luminance and detail. In the first case the nearest neighbor
green is one pixel dimension away. In the second, the nearest
neighbor green is 1.414 pixel dimension away. Thus the first ccd
can resolve two points that are 0.707 closer than the second. Now
how many pixels must the second have (in the same physical size ccd
chip) to get the same resolving power. It must have about twice as
many to get the nearest neighbor distance down. Thus the comment
that the Fovean ccd has twice the resolution in the sense that you
would have to put twice the number of ccd cells (Bayer pattern) in
the same size ccd to get the approximately the same resolving power
as the Fovean ccd.

 

[alistairsyme]

The human eye is not most sensitive to green. Sensitivity peaks at 555nm (which is yellow) and falls away on a bell curve. Sensitivity drops to almost nothing at 440nm and 680nm. Sunlight is not green, it is white. Radiometrically, the strongest visible rays from the sun are actually red. However, because of the spectral response curve, the strongest rays we perceive are yellow. Chlorophyll is green because those are the wavelengths the plant is NOT absorbing. Humans are sensitive to green simply because green is the color of much of nature. If plants were blue, that's the color we'd be sensitive to. Under low light conditions, we use the rods in our retinas, which are essentially monochromatic.

Re: Foveon X3: Why Greenx2=Resolutionx2? Wowx3 Images?
Question 1. Why does Resolution depend on Green?

Cuz:
1 We have 50% of green sensors in our eyes, and 25% of reds and
blues each.
2 Our green sensors are working under low light conditions, so
green light is more important for our eyes, and more green is
accepted as normal by our video-procesor (in brain). Have you seen
"The Matrix"? Lets say, green light for us (people) is like B&W,
ye, maybe it is difficult to understand, or maybe I found bad
examples for explanations, I guess oculists will explain you better
(I'm serious!).

--
Excal

 

[Leon Wittwer]

Mark, We are on the same wavelength. I've always been uncomfortable with the common definition of resolution for digital cameras as the total number of ccd cells. A more technically correct statement is that the Fovean would have about 1.4 times better resolving power than the corresponding Bayer pattern. Regarding your comment about "no individual sensor data is available from the Bayer array," That may not be correct. I would assume that the original color measurements in a ccd with the Bayer pattern come through unscathed and only the missing values are derived by the fancy interpolation schemes. I also doubt that processing is done in groups of 2x2 pixels. This would throw a lot of useful information away that would be used to fill in the color holes. I have seen some versions of the math formulas used and they were not "grouped."

That was actually my point. It doesn't have "twice" the
resolution, it has - maybe - 1.4 times the resolution. The
measured result may not be exactly 1/sqrt(2), because no individual
sensor data is available from the Bayer array, only merged results
from groups of 2x2 pixels. Doubling the number of green pixels and
using their individual values may not be exactly the same as (for
example) doubling the sensor count of a Bayer CCD. But the final
result is likely to be an increase in the number of resolveable
line pairs by a factor of about 1.4.