Re: [pygame] 10 bits per color

[James Paige <Bob@xxxxxxxxxxxxxxxxxxx>]

On Thu, Oct 01, 2009 at 09:57:32AM -0700, Brian Fisher wrote:
>    Your facts are all basically correct, but some things you are missing is
>    the fact that human vision is both dynamic in terms of it's ability to
>    perceive ranges of intensity and color and able to support a very wide
>    contrast ratio (around 1,000,000 to 1) compared to what contrast ratio
>    monitors are currently pumping out (somewhere between 350:1 to 1000:1)
>    (btw, our perception is basically decibel based, so it's more like the
>    best monitors are 1/4th of what we can do rather than 1/1000th)
>     
>    What that means is our monitors are pretty much crap when it comes to
>    maxing out our eyes contrast-wise, and that even though our eyes have
>    limited color perception, the limits and use of that limited color
>    perception depend on what we are looking at - or to put another way, which
>    7-10 million colors the average person is distinguishing depends largely
>    on what colors and intensities there are to look at. (btw, this is why
>    contrast ratio doesn't matter so much for home or movie theatres with
>    paltry contrast ratios of 1:500 but the environment is blacked out - our
>    vision readjusts very well to just using the range provided)
> 
>    The big thing about all this new monitor stuff is the new high-contrast
>    displays, as Pierre said "new TV with
>    retro light using LEDs has higher contrast (up to 2000000:1 wich is about
>    126 DB dynamic range)". People who have seen those new monitors have told
>    me the pictures looked like real life, that it was like looking out a
>    window, not at a monitor.
> 
>    With those new high contrasts though, if you aren't using the full
>    contrast range for a particular scene, RGB888 can be way too small. So
>    more range is needed if you wanna do something like go from a cave to the
>    out of doors - if the cave is half as bright with RGB888, you dropped half
>    your range, to RGB777, and your eyes can start seeing bands and such
>    better.

So the big difference, if I inderstand you correctly, is: RGB888 is over 
16 million colors MAX, but the average human eye, being dynamic, 
distinguishes somewhere around 7 to 10 million colors AT A TIME.

>    RGB is designed to be close to our rods and cones, which for most people
>    see an R with very good color range, a G with good color range, and a B
>    with mostly OK color range (relatively speaking). That's why many
>    restricted bit color schemes with uneven bit allocation put the extra bits
>    in the R or G but never the B. But there are actually some people (I've
>    heard they are mostly if not all women) with an extra cone (I think) that
>    is pretty close to the B, and those people have amazing color perception
>    much much better than RGB888, and usually work in color and print related
>    fields cause they can do things like match paint samples and colors at a
>    level beyond what us normal people can.

I have heard of that! Tetrachromatism!

Apparently the most common forms of red-colorblindness and 
green-colorblindness are not that the red or green cones are missing, 
but that they are present but picking up the wrong wavelengths. So if 
you are Red-blind that means your cones are GgB Green, Different Green, 
and Blue. And if you are green-blind then your cones are Red, Different Red, 
and Blue. RrB

Both mutations are carried on the X chromozome, and both are recessive 
traits. Since women have two copies of the X chromosome, they rarely 
have any colorblindness, because they almost always have a "good" copy 
of the Red or Green gene on the other X, but men having just one X are 
far more likely to have colorblindness.

Tetrachromatism (If I recall correctly) happens when a woman gets one 
different kind of colorblindness on each X. Somehow, sometimes this 
results in the "Other Red" and "Other Green" cones combining to behave 
like a population of "Orange" cones, so her vision is effectively 
Red-Orange-Green-Blue and she can see orange as if it was a primary 
color, instead of as a secondary color like most of the rest of us do.

---
James Paige