[Mongoose]

Not to dig up those squares again...but they appear as three distinct shades of gray to me.  What does that mean from a perception standpoint?

[watsisname]

Do they really?

Sometimes I feel like one of them is a different shade, but it alternates, and if I continue staring at it lots of tracers and funky lines flow over the image and I start sweating real hard as a vortex opens and Bugs Bunny grins at me through it and now I can't leave my room but wait there is something on the wall oh wow it's so soft!

[MP-Ryan]

Not to dig up those squares again...but they appear as three distinct shades of gray to me.  What does that mean from a perception standpoint?

Read my last post on page 3 and you'll figure it out =)

Hint:  Minimum 2 cones must fire to determine colour perception based on wavelength and intensity.

[Mongoose]

No, I understand that...I just mean that Herra seemed to be suggesting that he saw all three boxes as the same exact shade, whereas I can tell them apart very easily.  I was thinking it might be a monitor thing.

[MP-Ryan]

No, I understand that...I just mean that Herra seemed to be suggesting that he saw all three boxes as the same exact shade, whereas I can tell them apart very easily.  I was thinking it might be a monitor thing.

Oh!

Yeah, probably your monitor.  I've looked at them on four different monitors today and they were all the same shade.

[Luis Dias]

I didn't get your point either.  What on earth was it?

People here still confuse empirical reality for reality itself. They are thinking that if they are able to see RED, and name RED, and share the "experience" of RED with every other human being, that RED exists "by itself", "out there", even if humans didn't exist.

This is basic metaphysical thinking. The belief that "things exist beyond humans". At this point people get confused, and perhaps think that I'm a solipsist, that I think that the universe only exists when I think or live in it. It's way more subtle than that. It's semantical. The universe existed and will exist even if no humans exist any more, but by then the word "RED" becomes meaningless. Not because it "doesn't exist per se", but because that sentence becomes meaningless by itself.

"RED" is only meaningful to humans. You need humans to define "RED". You can even try to be utterly objective and declare that it is the wavelenght XPTO, but even that is hanging in a lot of human assumptions and needs. Rocks won't care about this definition.

This debate of what is color, and if it "exists" by "itself" is pretty old, and the term used for the experience of the color by humans is "QUALIA". Does QUALIA exist outside the human brain?

The thing that I was trying to say to Battuta is that people simply have too much difficulty in realizing that they cannot see things "as they are", because that is a metaphysical pipe dream. A meaningless platonic exercise. What we can do is formulate words that convey how we can explain the models we use that predict astonishingly well what happens when we open our eyes and what we see in the world. And that's all we need.

[Herra Tohtori]

Not to dig up those squares again...but they appear as three distinct shades of gray to me.  What does that mean from a perception standpoint?

It probably means your display's calibration is not ideal. The basic mechanism behind those squares is that each pixel on your screen consists of three sub-pixels: Red, green and blue. Due to the values of colours, each sub-pixel is either on, or it is off.

Each pixel lit looks like this:
███

and each pixel shut down looks like this:

███

Cyan-red subpixel pattern looks like this:

██████
██████

Broken into sub-pixels, it looks like this:

███ ███
███ ███


When it repeats, it looks like this:

███ ██████ ███ ███ ███ ███ ███ ███ ███ ███ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ███ ███ ███ ███ ███ ███ ███ ███ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ███ ███ ███ ███ ███ ███ ███ ███ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ███ ███ ███ ███ ███ ███ ███ ███ ███
███ ██████ ██████ ██████ ██████ ██████ ███


So you can basically see that overall exactly half of the sub-pixels are lit, and half are shut down. This is effectively the exact same thing as dithering full white and full black pixels similarly; only the sub-pixel arrangement changes line by line.


This exact same distribution (with slightly varying subpixel order for each line) should repeat for all the squares, regardless of the colour of the pixels - the structure of the display renders them effectively similar to what dithered black-white checker board would be. Sub-pixel layout of your display will also effect the ordering of each lines (I used horizontal RGB layout which is I think the most common).

If your display doesn't do this, then I would look into some calibrations, specifically RGB gamma curves and possibly colour temperature, but I'm not certain what type of monitor would display the squares significantly differently...

Also, my pixels are not square.


EDIT: Here are the yellow-blue and magenta-green patterns:

██████
██████

███ ███
███ ███

███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███



██████
██████

███ ███
███ ███


███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███
███ ██████ ██████ ██████ ██████ ██████ ███


The last one is particularly interesting because it spreads the sub-pixel distribution evenly in an on/off pattern.

[Mongoose]

I'll assume it's because I'm running an almost-seven-year-old CRT which may or may not be on the fritz, and just leave it at that.

[Bobboau]

I can see a clear difference between them on my laptop, but on the main PC their is no difference.

monitor thing.

[Luis Dias]

Throw your laptop to the garbage!

[castor]

They managed to interface with the visual nerve of a cat. They have his data, but not his interpretation.
Yeah, I'm not sure what this argument is about..

[Bobboau]

it has nothing to do with that, this argument is about color.

[Snail]

it has nothing to do with that, this argument is about color.

or the non-existance thereof

[Mars]

It does exist. Just in our heads - basically it exists in-so-far as anything else we perceive does.

[Luis Dias]

Like shapes.

[watsisname]

WHAAAAAAT?  Okay I'd like an explanation of that one.

I'd say that things like color, sound, tastes, our sensations of hot and cold, etc exist only in our heads, but shapes?  I'm pretty sure a spherical object is in fact spherical regardless of my perception of it.  Or maybe I just don't understand what you mean by "shape".

[Ghostavo]

I think he's talking about image processing performed by our brain.

Off the top of my head, I remember that we do insanely good image segmentation. So good, that we sometimes segment stuff that isn't supposed to be there.

[Shivan Hunter]

All well and good but unfortunately for Battuta colors definitely do exist.

On graphs.

And quarks.



I remember reading some stuff about perception a while ago, it's amazing how little is directly representative of what actually exists.

[Mongoose]

Quarks have flavor, too, proving that the scientist who came up with that nomenclature had a severe case of the munchies at the time.

[Luis Dias]

WHAAAAAAT?  Okay I'd like an explanation of that one.

I'd say that things like color, sound, tastes, our sensations of hot and cold, etc exist only in our heads, but shapes?  I'm pretty sure a spherical object is in fact spherical regardless of my perception of it.  Or maybe I just don't understand what you mean by "shape".

What do you mean an object is "in fact" spherical? Did you ask it, and it replied, "yeah, I'm spherical, congrats here are 10 points for your correct answer"? A sphere is an abstract shape, i.e., it is human made simplification, a mathematical caricature that we find useful to categorize stuff. You'll be in pains to actually find something that is in all its "reality" (whatever the hell that is) actually spherical.

The only "real" spheres I can remember are the ones that I define on AutoCAD. But that's tautological, you see.

I remember reading some stuff about perception a while ago, it's amazing how little is directly representative of what actually exists.

What you *really* mean is that some apparatus perceives "stuff" in a very different manner than your own eyes do, or that our own models of physics are not really entirely compatible with our own perception of the phenomena they describe. "What actually exists" is in the realm of transcendence.