6 ms·

Optical illusions that show how color can trick the eye

62 points by octoploid 12y ago

pavel_lishin 12y ago
These discussions always remind me of David Langford's work: http://www.infinityplus.co.uk/stories/blit.htm http://www.infinityplus.co.uk/stories/blit.htm http://www.lightspeedmagazine.com/fiction/different-kinds-of-darkness/ http://www.lightspeedmagazine.com/fiction/different-kinds-of... http://ansible.uk/writing/c-b-faq.html http://ansible.uk/writing/c-b-faq.html
- DanBC 12y ago
  I loved Blit! I used to subscribe to Interzone when Blit was published. Those Interzone anthologies were excellent. Whoever owns the rights should sell them as ebooks if they don't already. (EDIT: this is I think the third mention of Blit on HN)
  - pavel_lishin 12y ago
    I think I might end up having to just buy Langford's "Other Kinds of Darkness" somewhere; none of my local libraries have it available for checkout.
niccl 12y ago
I know it's slightly off topic but I've been fascinated with the idea of blind people having 'optical' illusions. Eg does the cafe wall illusion (http://en.wikipedia.org/wiki/Café_wall_illusion http://en.wikipedia.org/wiki/Café_wall_illusion) work if you're blind and investigating a real cafe wall with that pattern using your fingers? Or are there other things that _do_ create perceptual illusions because of the different way blind people experience the world?
- ars 12y ago
  The illusions mostly happen in the eye, not in the brain. So I don't think they will work for touch. The eye does not transmit "dots" of color to the brain, but rather processes images very much. Some of the "layers" that are transmitted are edge, motion, and color. So motion illusions happen in the eye.
jader201 12y ago
I never joined the discussion about the dress (I was actually removed from technology pretty much until after the whole debate died down, after which I experienced another interesting phenomenon). But what is fascinating to me is that the day following the debate, I saw the image in Wired [1] and for the life of me could not possibly see black and blue no matter how hard I tried. I just now read this article, looked at the image at the bottom, then tried to find the original Wired image, and now cannot see white and gold. The influence is so strong that part of me almost thinks it's not the same image. It sort of reminds me of when I first figured out how to "see" those stereograms, and how once you know how to see one of them, seeing any of them is easy. [1] http://www.wired.com/2015/02/science-one-agrees-color-dress/ http://www.wired.com/2015/02/science-one-agrees-color-dress/
- ars 12y ago
  I had the same effect. One day I see gold and no matter how I try I can not make it black. The next day, with the exact same image and background, the parts that were gold are now solid black, and I can not understand how they can possibly be gold. I can understand how different eyes might see it differently, but how my own vision changed, and so completely, I don't understand. It's like these images that trick a neural network: http://www.wired.com/2015/01/simple-pictures-state-art-ai-still-cant-recognize/ http://www.wired.com/2015/01/simple-pictures-state-art-ai-st...
  - deleted 12y ago
    [deleted]
- jdmichal 12y ago
  I had an interesting experience with it. When I originally saw it, I could only see the blue-and-black. However, I had the image on the screen when I moved to grab something and went beyond the viewing angle of my screen, and it appeared gold-and-white. I then sat back down, and the dress stayed gold-and-white while the rest of the screen returned to normal. Fun times for the brain.
ZenoArrow 12y ago
Okay, I'm probably going to get marked down for this, but... with that whole "the dress" thing, am I wrong to think it's not just Photoshop and/or the dress coming out different colours in the image depending on the light? Take this example... http://assets-s3.usmagazine.com/uploads/assets/articles/83714-the-dress-sales-are-up-retailer-looking-into-white-and-gold-version/1425052031_the-dress-retail-467.jpg http://assets-s3.usmagazine.com/uploads/assets/articles/8371... Now does everyone seeing that see bronze and light blue on the left, and dark blue and black on the right? Supposedly these are images of the same dress. If anyone suggests they're seeing the colours differently on this example, I'll be genuinely surprised, but at the moment I find that unlikely. EDIT: ...and the downvotes have started. How predictable.
- abroncs 12y ago
  It's definitely the light. It's a black/blue dress but the sun makes it have a hint of gold.
- gohrt 12y ago
  The reason the dress picture is interesting is that it is a real-world instance of the checkershadow illusion http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html http://web.mit.edu/persci/people/adelson/checkershadow_illus...
  - leppr 12y ago
    Yes, it combines that with the color hue equivalent: http://img.washingtonpost.com/blogs/wonkblog/files/2015/02/yellow-blue-dogs.jpg http://img.washingtonpost.com/blogs/wonkblog/files/2015/02/y... On another note, I'm wondering if people did comparisons on whether the size at which you viewed the robe had any effect on people's choice. Personally I can't see it as white because there are enough cues in the background that indicate that there isn't a strong blue light lighting the dress from the front. On the other hand if I shrink the image and squint, I can imagine it being a sort of backlit photo where the blue tint would just be a result of outdoor atmospheric diffusion and the contrast with yellow sunlight.
- ronilan 12y ago
figseed 12y ago
So the popular hypothesis is that the dress is black and blue. I have now seen so many different sites and authors try to explain the phenomenon, all based on the "proof" that some random woman named Caitlin McNeil who first offered the disputed picture originally claiming she saw it as white and gold in the picture, saw it some days later in person, said it was definitely black and blue and offered a picture of an indisputably black and blue dress that appeared to be identical or at least too similar to be able to tell a difference definitely. The issue to me is that I'm seeing sites like Wired and I fking love science explain how the dispute is possible based on optical illusions and ultimately say that the dress is black and blue because of the other image and the claims of a dress manufacturer with no credence to possibility that the dress in one picture may be different than the dress in the others and that dressgate might just be an elaborate hoax. The thing is, you can just as easily explain why the dress is white and gold and appears blue and black to some people given the intense back lighting in the disputed image implying sunlight in the background and the effects of reflected UV light can play on shaded white objects (think black uv lights) or effects like solarization that can happen in digital imagery. The thing is, I'm sick of hearing the dress is blue and black because "science", when science hasn't been involved in anyone's "proof" of the effect. What you have is a hypothesis. Want to make it a viable theory? Take the black and blue dress or one of the identical ones from the designer claiming that's their black and blue dress and recreate an identical image that appears white and gold with the same tonal qualities and environmental lighting. Until someone does that, I don't think there's any reason to continue "proving" why the dispute exists with non-science or arguing about this nonsensical bullshieza as it has become a gargantuan distraction from reality whether or not it was originally meant to be.
- deleted 12y ago
  [deleted]
- vacri 12y ago
  The main article describes differences in perception of colours due to surrounding colours. It's a well-researched topic in science. I learned stuff like this in my neurophysiology degree over 20 years ago. Dismissing it as "'because science'" and demanding that there be an invalidated null hypothesis before you can draw on scientific knowledge is just being wilfully obstructive. Do you really re-do all your basic experiments before you conduct the one that rests on them?
georgemcbay 12y ago
This has been covered on HN before (IIRC that's where I first read about it), but my favorite vision color "trick" is the McCollough Effect, mostly because of how long it lasts (weeks in my case, YMMV): http://www.cheswick.com/ches/projects/me/ http://www.cheswick.com/ches/projects/me/
JohnHammersley 12y ago
If anyone's interested in recreating some of these, LaTeX provides a neat way to do so: https://www.overleaf.com/gallery/tagged/illusions https://www.overleaf.com/gallery/tagged/illusions
rasz_pl 12y ago
http://xkcd.com/1492/ http://xkcd.com/1492/ I suspect people seeing white/gold live/grew up in sunny climate with blue sky, sea?, maybe blue walls/wallpaper in their bedroom. Basically people primed for seeing things illuminated by blue tinted light.

62 points by octoploid 12y ago

These discussions always remind me of David Langford's work: http://www.infinityplus.co.uk/stories/blit.htm http://www.infinityplus.co.uk/stories/blit.htm http://www.lightspeedmagazine.com/fiction/different-kinds-of-darkness/ http://www.lightspeedmagazine.com/fiction/different-kinds-of... http://ansible.uk/writing/c-b-faq.html http://ansible.uk/writing/c-b-faq.html

DanBC 12y ago
I loved Blit! I used to subscribe to Interzone when Blit was published. Those Interzone anthologies were excellent. Whoever owns the rights should sell them as ebooks if they don't already. (EDIT: this is I think the third mention of Blit on HN)
- pavel_lishin 12y ago
  I think I might end up having to just buy Langford's "Other Kinds of Darkness" somewhere; none of my local libraries have it available for checkout.

niccl 12y ago

I know it's slightly off topic but I've been fascinated with the idea of blind people having 'optical' illusions. Eg does the cafe wall illusion (http://en.wikipedia.org/wiki/Café_wall_illusion http://en.wikipedia.org/wiki/Café_wall_illusion) work if you're blind and investigating a real cafe wall with that pattern using your fingers? Or are there other things that _do_ create perceptual illusions because of the different way blind people experience the world?

ars 12y ago
The illusions mostly happen in the eye, not in the brain. So I don't think they will work for touch. The eye does not transmit "dots" of color to the brain, but rather processes images very much. Some of the "layers" that are transmitted are edge, motion, and color. So motion illusions happen in the eye.

jader201 12y ago

I never joined the discussion about the dress (I was actually removed from technology pretty much until after the whole debate died down, after which I experienced another interesting phenomenon). But what is fascinating to me is that the day following the debate, I saw the image in Wired [1] and for the life of me could not possibly see black and blue no matter how hard I tried. I just now read this article, looked at the image at the bottom, then tried to find the original Wired image, and now cannot see white and gold. The influence is so strong that part of me almost thinks it's not the same image. It sort of reminds me of when I first figured out how to "see" those stereograms, and how once you know how to see one of them, seeing any of them is easy. [1] http://www.wired.com/2015/02/science-one-agrees-color-dress/ http://www.wired.com/2015/02/science-one-agrees-color-dress/

ars 12y ago
I had the same effect. One day I see gold and no matter how I try I can not make it black. The next day, with the exact same image and background, the parts that were gold are now solid black, and I can not understand how they can possibly be gold. I can understand how different eyes might see it differently, but how my own vision changed, and so completely, I don't understand. It's like these images that trick a neural network: http://www.wired.com/2015/01/simple-pictures-state-art-ai-still-cant-recognize/ http://www.wired.com/2015/01/simple-pictures-state-art-ai-st...
- deleted 12y ago
  [deleted]
jdmichal 12y ago
I had an interesting experience with it. When I originally saw it, I could only see the blue-and-black. However, I had the image on the screen when I moved to grab something and went beyond the viewing angle of my screen, and it appeared gold-and-white. I then sat back down, and the dress stayed gold-and-white while the rest of the screen returned to normal. Fun times for the brain.

ZenoArrow 12y ago

Okay, I'm probably going to get marked down for this, but... with that whole "the dress" thing, am I wrong to think it's not just Photoshop and/or the dress coming out different colours in the image depending on the light? Take this example... http://assets-s3.usmagazine.com/uploads/assets/articles/83714-the-dress-sales-are-up-retailer-looking-into-white-and-gold-version/1425052031_the-dress-retail-467.jpg http://assets-s3.usmagazine.com/uploads/assets/articles/8371... Now does everyone seeing that see bronze and light blue on the left, and dark blue and black on the right? Supposedly these are images of the same dress. If anyone suggests they're seeing the colours differently on this example, I'll be genuinely surprised, but at the moment I find that unlikely. EDIT: ...and the downvotes have started. How predictable.

abroncs 12y ago
It's definitely the light. It's a black/blue dress but the sun makes it have a hint of gold.
gohrt 12y ago
The reason the dress picture is interesting is that it is a real-world instance of the checkershadow illusion http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html http://web.mit.edu/persci/people/adelson/checkershadow_illus...
- leppr 12y ago
  Yes, it combines that with the color hue equivalent: http://img.washingtonpost.com/blogs/wonkblog/files/2015/02/yellow-blue-dogs.jpg http://img.washingtonpost.com/blogs/wonkblog/files/2015/02/y... On another note, I'm wondering if people did comparisons on whether the size at which you viewed the robe had any effect on people's choice. Personally I can't see it as white because there are enough cues in the background that indicate that there isn't a strong blue light lighting the dress from the front. On the other hand if I shrink the image and squint, I can imagine it being a sort of backlit photo where the blue tint would just be a result of outdoor atmospheric diffusion and the contrast with yellow sunlight.
ronilan 12y ago

figseed 12y ago

So the popular hypothesis is that the dress is black and blue. I have now seen so many different sites and authors try to explain the phenomenon, all based on the "proof" that some random woman named Caitlin McNeil who first offered the disputed picture originally claiming she saw it as white and gold in the picture, saw it some days later in person, said it was definitely black and blue and offered a picture of an indisputably black and blue dress that appeared to be identical or at least too similar to be able to tell a difference definitely. The issue to me is that I'm seeing sites like Wired and I fking love science explain how the dispute is possible based on optical illusions and ultimately say that the dress is black and blue because of the other image and the claims of a dress manufacturer with no credence to possibility that the dress in one picture may be different than the dress in the others and that dressgate might just be an elaborate hoax. The thing is, you can just as easily explain why the dress is white and gold and appears blue and black to some people given the intense back lighting in the disputed image implying sunlight in the background and the effects of reflected UV light can play on shaded white objects (think black uv lights) or effects like solarization that can happen in digital imagery. The thing is, I'm sick of hearing the dress is blue and black because "science", when science hasn't been involved in anyone's "proof" of the effect. What you have is a hypothesis. Want to make it a viable theory? Take the black and blue dress or one of the identical ones from the designer claiming that's their black and blue dress and recreate an identical image that appears white and gold with the same tonal qualities and environmental lighting. Until someone does that, I don't think there's any reason to continue "proving" why the dispute exists with non-science or arguing about this nonsensical bullshieza as it has become a gargantuan distraction from reality whether or not it was originally meant to be.

deleted 12y ago
[deleted]
vacri 12y ago
The main article describes differences in perception of colours due to surrounding colours. It's a well-researched topic in science. I learned stuff like this in my neurophysiology degree over 20 years ago. Dismissing it as "'because science'" and demanding that there be an invalidated null hypothesis before you can draw on scientific knowledge is just being wilfully obstructive. Do you really re-do all your basic experiments before you conduct the one that rests on them?

georgemcbay 12y ago

This has been covered on HN before (IIRC that's where I first read about it), but my favorite vision color "trick" is the McCollough Effect, mostly because of how long it lasts (weeks in my case, YMMV): http://www.cheswick.com/ches/projects/me/ http://www.cheswick.com/ches/projects/me/

JohnHammersley 12y ago

If anyone's interested in recreating some of these, LaTeX provides a neat way to do so: https://www.overleaf.com/gallery/tagged/illusions https://www.overleaf.com/gallery/tagged/illusions

rasz_pl 12y ago

http://xkcd.com/1492/ http://xkcd.com/1492/ I suspect people seeing white/gold live/grew up in sunny climate with blue sky, sea?, maybe blue walls/wallpaper in their bedroom. Basically people primed for seeing things illuminated by blue tinted light.