[OT] what RGB is blue?

[Nonsanity]

Go with the math. You can't trust your eyes.

http://boingboing.net/2008/02/08/color-tile-optical-i.html

Well, your eyes aren't really the culprit, if not color blind. We can see
three color ranges at the cellular level.

http://en.wikipedia.org/wiki/Cone_cell

Your brain is the thing that's broken in that regard, as the illusion
demonstrates. It gets in the way of direct interpretation of reality, as it
always does. Not that our eyes are all that well put together... The retina
is inside-out, so that light has to pass through tissue before it reaches
the photo-receptive rods and cones on the back. (Hence the blind spot, where
the wiring on the front - which the light hits first - has to punch through
the retina to connect with the brain.)

But no surprise there since you can see mammal embryos going through the
earlier, simpler evolutionary forms of eye as each more advanced layer of
instructions turns on and reshapes it further. That's evolution for you...
Perfection it ignores in favor of "just good enough to breed". :)

 ~ Chris Innanen
 ~ Nonsanity


>> On 1 jul 2011, at 11:39, Tiemo Hollmann TB wrote:
> >>
> >>> Hello,
> >>>
> >>> I am taking the mousecolor at different points from an image by script
> >> (not
> >>> by clicking). I would like to analyse if the color I've taken is a
> "kind
> >> of
> >>> blue", or another color. I want to change the backgroundcolor of an
> >> image.
> >>> The background is always blue, but different blues and changing over
> the
> >>> background. So what I want to do is to verify, what is background and
> >> what
> >>> is foreground of my image.
> >>>
> >>> 100% pure blue would be 0,0,255. But for a human being 25,75,130
> >> (greyblue)
> >>> is also still blue, but 240,20,180 is pink, though the third RGB value
> is
> >>> higher as in my greyblue.
> >>>
> >>> So I can't just check only the third RGB value, neither the sum or
> cross
> >>> total. Has anybody ever heard, if you can define at all by math "what
> is
> >>> blue"?
> >>>
> >>> Any color specialist around here?
> >>>
> >>> Tiemo
>