
All the balls are the same color: brown - vinnyglennon
https://twitter.com/chazfirestone/status/1139533381597847555
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emeraldd
The smaller the image, the more effective that illusion. Looking at it on my
20+" screen at almost fullscreen I can look at individual alls and clearly see
the as "brown." But with a smaller image, even looking directly at the ball,
I'm seeing more of the color of the bar than the color of the bar. This makes
me wonder if there's a physical aspect to the way this illusion works, maybe
something to do with structure of the eye?

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CodiePetersen
In the eye, cells only fire if the signal between the neighbors is great.
There is also higher resolution concentrated at the center and drops off as
you move away. Additionally the brain processes signals in context of the last
signal it received. So if you put that all together, on a small screen the
gaps are small enough that in the center of the eye, fovea, it will be
processing more red than brown. You can also see the ball is actually not just
brown. Its shaded which reduces the "fire near highly different neighbors"
effect. The red though is solid.

There is also the fact that the eyes resolution drops off towards the edge.
This makes the effect even harsher in the corner of your eye. As your eye
moves from ball to ball your brain will be processing the new higher
resolution versions based on the previous versions you saw in the corner of
your eye. That effect fades away but your eye is actually always moving doing
something called saccades, on a small screen with many prominent points it
will do it a lot.

With a big screen alot of that goes away. The gaps are larger. The brown fades
more slowly from light to dark so is percieved as a stronger color. Objects
are larger so saccades will be less effective because they will be searching
fewer objects rather than many in a tight screen. Lastly the lower resolutions
at the edge of your eye will pick up more brown as well.

So there most definitely is physical aspects.

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joveian
The color of the brown is also not the same: in addition to the several pixel
transition area which depends on the stripe color there are slightly red,
green, and blue tinted patches in the rest of the brown that differ based on
the stripe color, which helps create the neon glow effect. Calling the balls
all the same color seems to be entirely incorrect.

I also see an "egg" illusion where it looks like the lower left of the ball is
actually flat but the rest is a dome.

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Theodores
This poses a problem for machine learning. Optical illusions exist in real
life, but when does your AI decide to go with 'brown' and when does it imagine
to go with 'what humans would think'?

I look forward to a robot future where us humans can have a joke and catch out
robots by enjoying these optical illusions knowing 'they' don't get it.

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tomxor
I believe this illusion is exploiting a quirk of human sensory vision so any
machine learning will not be affected. It's the same property that most video
encodings and compression algorithms exploit: Our colour and luminance
perception does not have equal fidelity, i.e we dont sense as much detail in
colour, where as we can sense more detail in luminance... in this case it
means we can perceive the stripes, and given stripes alone we can just about
discern their colour, but when mixed with a background colour it effectively
blends the colour without blending the luminance.

I think this might be the same biological reason that we can't perceive much
(or any) colour in low light, rods vs cones.

TL;DR our retinas are not CCDs they are a patchwork of two discrete
components.

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MrStonedOne
>I believe this illusion is exploiting a quirk of human sensory vision so any
machine learning will not be affected.

That's the point my dude.

Humans see an optical illusion, robots do not. Meaning ML algos that care
about seeing things as humans do have a conundrum.

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peteretep
Why wouldn’t the robots see it?

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meuk
If you squint your eyes, the balls look red, blue, and green, but that's to be
expected if there are colored bars over them. And if you don't squint your
eyes, the "balls" look about the same color... So what's the illusion?

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tobr
You could even say that _actually_ , the balls _aren’t_ brown. They are made
up of pure red, green and blue subpixels on your screen.

It’s really not a particularly interesting illusion.

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mhb
You're suggesting that this wouldn't work if it were printed or a painting?

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tobr
No, I’m saying it’s the same type of illusion. Small areas of color blend
together and look like a single color to our eyes. (CMYK printing of course
works on the same principle)

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malaxii
That's not so clear. The LCD subpixels and CMYK dots may well be below the
optical/retina resolution of the eye, in which case it's not really an
illusion at all as it's already in the signal data the brain receives. This is
quite likely so, because you cannot see those dots individually even with
concentration. The same likely goes for squinting your eyes as they become
optically unfocused.

In contrast, here the issue is undoubtedly in how the brain interprets the
signal data, i.e., an illusion.

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tobr
Subpixels of modern high resolution screens are below what a normal eye can
resolve, but that really isn’t necessary to perceive apparent shades of color.
You get the same experience even with a very low resolution RGB screen, where
you can distinguish the subpixel elements easily.

It’s not right to say that the balls are “brown”, when they are in fact
striped brown and red/green/blue. It’s like saying that a zebra is black if
you just ignore the white.

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choeger
The following blew my mind. I asked my four year old twins and both told me
"brown, brown, brown. All balls are brown".

Can it be that such an illusion is learned?

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gowld
If you look at each ball one at a time, it's obvious that each is brown. The
effect only works if you look at the balls with your peripheral vision and
then make a summary judgement.

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phs
I'm zooming in on one pair until each is about one hand-width in diameter. The
effect is still present for me.

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Marazan
The point of this illusion is that it goes against what we expect for colour
discrimiation. We would expect the balls where the red bars going over the top
to look less red not more red.

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pauldelany
It's also worth checking out his research:
[https://twitter.com/chazfirestone/status/1109105677006487552](https://twitter.com/chazfirestone/status/1109105677006487552)

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cm2012
On mobile this is a perfect illusion, unless you physicslly hide all but one
ball.

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libertas
I think it is the same principal as simultaneous contrast.

[https://youtu.be/FIwqyyFLo_A](https://youtu.be/FIwqyyFLo_A)

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faissaloo
You can actually see the real color if you focus on one and pay attention to
your peripheral vision

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fourier_mode
Though the shade of brown is different, right?

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Steel_Phoenix
Doesn't seem to be. I edited out all the lines with Photoshop, and what
remained looked identical.

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gowld
Yes, that's how RGB pixelization works.

