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>> A fun (but impractical and frustrating) variant of this feature is to have the image change as soon as the viewer looks away. So you’re looking at a painting

by Phemist 11y ago

>> A fun (but impractical and frustrating) variant of this feature is to have the image change as soon as the viewer looks away. So you’re looking at a painting, glance away to another room, and look back to find a new painting hanging on the wall. Re this comment. There is this thing called "saccadic masking", the gist of which is that we are effectively blind while our eyes move from focusing on one position to the next. Depending on the "distance" (angle) traveled by the eye, this can last up to tens of milliseconds. Enough time to do some cool stuff! One of the studies that conclusively showed this effect, a fairly long time ago, had participants wear some elaborate headgear that allowed the researchers to track where the eyes of their participants were looking at. They had them look at a standard sentence like "the quick brown fox jumped over the lazy dog", but with a twist! Every word in the sentence was masked, except for the word the participant would be focusing on at that moment. So if he focused on the word fox, the screen would show "xxx xxxxx xxxxx fox xxxxxx xxxx xxx xxxx xxx". Whenever the system detected a saccade by the eyes, they would recalculate which word the participant would be looking at (e.g. switch to dog), and changed the display of the screen accordingly, now showing "xxx xxxxx xxxxx xxx xxxxxx xxxx xxx xxxx dog" Participants were asked if they noticed anything strange about the sentence, but they reported there was nothing strange about it! (Disregarding having a heavy set of mirrors strapped to your head). My point: If you were able to detect saccades of the eyes, and relatively accurately calculate their position, you could have the region of the image that's unattended be colourful noise, the theory says that your visitors would be none the wiser (of course this would break down with multiple people looking at the same image) Even cooler: procedurally re-generate parts of the image that are unattended, so that you're looking at an ever shifting image, but wouldn't quite be able to pin down what's happening. Similar to this video: https://www.youtube.com/watch?v=ubNF9QNEQLA https://www.youtube.com/watch?v=ubNF9QNEQLA

cocoflunchy 11y ago
This is also the principle behind foveated rendering (https://en.wikipedia.org/wiki/Foveated_imaging https://en.wikipedia.org/wiki/Foveated_imaging) where you only render the graphics in high detail where the viewer is looking, and use a low-res image for the rest with the goal of saving computing power. Big area of development right now for VR!
- Phemist 11y ago
  That's really cool! I'm not 100% sure, but what I remember from reading a few psych papers about this is that as long as the "mask" is similar to the original in a few easy to calculate sampling statistics (colour distribution, overall hue), it doesn't actually need to look anything like the original image, even calculating low-res imagery shouldn't be necessary. Our peripheral vision is just that bad (at least for static imagery, movement detection is actually pretty good). The foveated part is where the magic happens, and we've gotten pretty good at fooling ourself into believing this "foveated" part is much larger than it actually is.
  - kedean 11y ago
    Hey, something I know about! I actually worked on one of those research projects in college, programming the experiments. The idea is that there is a certain radius around the focal point where you stop being able to detect changes. I'm not sure what the final results were, but the theory was that you can calculate how blurry an image can be and still be discernable based on how far it is from the focal point of your vision. It was surprising how good people are at detecting changes in a blurry picture that's way out in their periphery.
    - Phemist 11y ago
      My prof used to joke that, whenever he'd discuss fovea and periphery, that if we had a fovea the size of our full field of view, we'd need a brain the size of an elephant to process all that information. It's interesting how we're very sensitive to sudden changes (thus movement) in our periphery, but are so bad at classifying/identifying static imagery. I remember reading about right eye and left eye dominance. Where they'd keep an image on the screen saccade invariant (ie, compensate for any saccades that were made). Slowing moving a letter/character/word/whatever to the edges of the participant's field of view and asking when the character was no longer legible. This happened surprisingly quickly, but at different positions for the left eye and right eye for pretty much all participants..
- chestervonwinch 11y ago
soneca 11y ago
Thanks for the explanation, that was great! I imagine you could play Where's Waldo without changing screens. Just "find the next Waldo" on an ever changing scenario. The moment you find one, another is created at other spot. Could be very addictive, although sounds kind of stressfull also.
- DonHopkins 11y ago
  It would be easier if each Waldo was looking or pointing towards the next one.
- hamburglar 11y ago
  You could also just have it decide exactly when it wants you to find Waldo. Imagine you had a Where's Waldo ipad app that had 20 different "pages" and you could set the amount of time it takes to get through them all so you could keep your kid busy for a guaranteed minimum time. :) Or even better, it's listening for you to say "ok, it's time to go in two minutes. Finish up," and it makes sure Waldo appears where the kid is looking just in time. The downside is when your kid finds out he's going to murder you.
  - Phemist 11y ago
    +1 for evil
  - morgante 11y ago
    That's brilliantly evil. Part of me wants to implement it just for the evil factor.
- scott_s 11y ago
  Or it places Waldo just outside of your field of focus, and constantly moves him as you look around.
DonHopkins 11y ago
This is what happens when I try to read text in a dream.
- Phemist 11y ago
  Basically the inverse being applied? Sentence fully displayed, with the word that's focused on masked...
ajuc 11y ago
This could be very useful for optimizing 3d videogames :) Basicaly rendering only part of screen each frame.
Phemist 11y ago
Found the article I was referencing - McConkie & Rayner (1975) - http://link.springer.com/article/10.3758/BF03203972 http://link.springer.com/article/10.3758/BF03203972
coldpie 11y ago
I apologize for the stupid response to your intelligent and well-written comment, but this reminded me of the classic "Creepy Watson" video, playing around with a poorly implemented follower AI in a budget video game. Audio not required, but recommended. https://www.youtube.com/watch?v=13YlEPwOfmk https://www.youtube.com/watch?v=13YlEPwOfmk
- joshschreuder 11y ago
  Crimes and Punishment, the follow up to that game is actually quite good. There's a new one out this year called The Devil's Daughter.
shasta 11y ago
Was it really just replacing each other letter with x? I can notice the string of x's with my peripheral vision. Also, the words must have been quite a bit farther apart than they are on my screen.
- nkrisc 11y ago
  Yes but you're also able to focus on the words made up entirely of 'x'. I don't think you can really judge the effect because 1) it's not the same effect here and 2) you already know about it now.
- Phemist 11y ago
  I was paraphrasing this from memory. The dependency is quite complex, it depends on the amount of degrees the text occupies in your field of vision, but also on the mode of reading you're in (very focused reading seems to narrow the fixation span). Also, please note that your eye makes constant micro-saccades (https://en.wikipedia.org/wiki/Microsaccade https://en.wikipedia.org/wiki/Microsaccade), and that the authors of the paper were probably compensating for these saccades as well, more or less. Quote from the actual paper This experiment has provided data which begin to answer the question about the size of the perceptual span during a fixation in reading. Although it may be possible in tasks other than reading for subjects to identify letters. word shapes, and word-length patterns some distance into the peripheral areas, in fluent reading this information appears to be obtained and used from a relatively narrow region. Thus. a theory of fluent reading need not suppose that word-shape and specific letter information is obtained from a region occupied by more than about three or four words during a fixation. and perhaps not that large if the span is not symmetrical around the point of central vision, a question not tested in the present study. Thus. it does not appear to be true that entire sentences are seen during a fixation; in fact. for most fixations. not even a complete phrase will lie within this area. So the "window" or "span" that needed to be un-masked was about 3-4 words wide (interestingly, this did not necessarily depend fully on the length of the words)
cooper12 11y ago
Your video reminded me of this selective attention test: https://www.youtube.com/watch?v=vJG698U2Mvo https://www.youtube.com/watch?v=vJG698U2Mvo. This Wikipedia article also seems to be related to the phenomenon and talks about the video too: https://en.wikipedia.org/wiki/Inattentional_blindness https://en.wikipedia.org/wiki/Inattentional_blindness.
- Phemist 11y ago
  Yes, this is always named in the same breath as my GP post, the gorilla video is a classic. The video I posted much the same thing. It makes you realise how much of what we perceive is really what we think we perceive
soared 11y ago
M$ research has AWESOME stuff on foveated graphics. They essentially track your eye movement and only render detail in the specific spot on the display you are looking out. Everything outside your eye's focus area is still rendered but a a much lower quality. Saves immense amounts of resources, imagine your gpu only having to render 20% of the screen at a time! http://research.microsoft.com/apps/pubs/default.aspx?id=176610 http://research.microsoft.com/apps/pubs/default.aspx?id=1766...
- Phemist 11y ago
  As an analog to lossy compression - lossy rendering?
danans 11y ago
There was an exhibit demonstrating a similar optical phenomenon in the Exploratorium (http://www.exploratorium.edu/ http://www.exploratorium.edu/) in San Francisco: The viewer watches a series of projected photographs of a streetscape with small differences between each (a pedestrian appears, a taxi disappears), but they don't see these changes because when the image changes, a small flash occurs, which somehow resets the optic system's change-detection system. The viewer can then press a button to suppress the interstitial flashes, and with no flashes, they can easily see the differences as they occur.
deleted 11y ago
[deleted]

by Phemist 11y ago

cocoflunchy 11y ago

This is also the principle behind foveated rendering (https://en.wikipedia.org/wiki/Foveated_imaging https://en.wikipedia.org/wiki/Foveated_imaging) where you only render the graphics in high detail where the viewer is looking, and use a low-res image for the rest with the goal of saving computing power. Big area of development right now for VR!

Phemist 11y ago
That's really cool! I'm not 100% sure, but what I remember from reading a few psych papers about this is that as long as the "mask" is similar to the original in a few easy to calculate sampling statistics (colour distribution, overall hue), it doesn't actually need to look anything like the original image, even calculating low-res imagery shouldn't be necessary. Our peripheral vision is just that bad (at least for static imagery, movement detection is actually pretty good). The foveated part is where the magic happens, and we've gotten pretty good at fooling ourself into believing this "foveated" part is much larger than it actually is.
- kedean 11y ago
  Hey, something I know about! I actually worked on one of those research projects in college, programming the experiments. The idea is that there is a certain radius around the focal point where you stop being able to detect changes. I'm not sure what the final results were, but the theory was that you can calculate how blurry an image can be and still be discernable based on how far it is from the focal point of your vision. It was surprising how good people are at detecting changes in a blurry picture that's way out in their periphery.
  - Phemist 11y ago
    My prof used to joke that, whenever he'd discuss fovea and periphery, that if we had a fovea the size of our full field of view, we'd need a brain the size of an elephant to process all that information. It's interesting how we're very sensitive to sudden changes (thus movement) in our periphery, but are so bad at classifying/identifying static imagery. I remember reading about right eye and left eye dominance. Where they'd keep an image on the screen saccade invariant (ie, compensate for any saccades that were made). Slowing moving a letter/character/word/whatever to the edges of the participant's field of view and asking when the character was no longer legible. This happened surprisingly quickly, but at different positions for the left eye and right eye for pretty much all participants..
chestervonwinch 11y ago

soneca 11y ago

Thanks for the explanation, that was great! I imagine you could play Where's Waldo without changing screens. Just "find the next Waldo" on an ever changing scenario. The moment you find one, another is created at other spot. Could be very addictive, although sounds kind of stressfull also.

DonHopkins 11y ago
It would be easier if each Waldo was looking or pointing towards the next one.
hamburglar 11y ago
You could also just have it decide exactly when it wants you to find Waldo. Imagine you had a Where's Waldo ipad app that had 20 different "pages" and you could set the amount of time it takes to get through them all so you could keep your kid busy for a guaranteed minimum time. :) Or even better, it's listening for you to say "ok, it's time to go in two minutes. Finish up," and it makes sure Waldo appears where the kid is looking just in time. The downside is when your kid finds out he's going to murder you.
- Phemist 11y ago
  +1 for evil
- morgante 11y ago
  That's brilliantly evil. Part of me wants to implement it just for the evil factor.
scott_s 11y ago
Or it places Waldo just outside of your field of focus, and constantly moves him as you look around.

DonHopkins 11y ago

This is what happens when I try to read text in a dream.

Phemist 11y ago
Basically the inverse being applied? Sentence fully displayed, with the word that's focused on masked...

ajuc 11y ago

This could be very useful for optimizing 3d videogames :) Basicaly rendering only part of screen each frame.

Phemist 11y ago

Found the article I was referencing - McConkie & Rayner (1975) - http://link.springer.com/article/10.3758/BF03203972 http://link.springer.com/article/10.3758/BF03203972

coldpie 11y ago

I apologize for the stupid response to your intelligent and well-written comment, but this reminded me of the classic "Creepy Watson" video, playing around with a poorly implemented follower AI in a budget video game. Audio not required, but recommended. https://www.youtube.com/watch?v=13YlEPwOfmk https://www.youtube.com/watch?v=13YlEPwOfmk

joshschreuder 11y ago
Crimes and Punishment, the follow up to that game is actually quite good. There's a new one out this year called The Devil's Daughter.

shasta 11y ago

Was it really just replacing each other letter with x? I can notice the string of x's with my peripheral vision. Also, the words must have been quite a bit farther apart than they are on my screen.

nkrisc 11y ago
Yes but you're also able to focus on the words made up entirely of 'x'. I don't think you can really judge the effect because 1) it's not the same effect here and 2) you already know about it now.
Phemist 11y ago
I was paraphrasing this from memory. The dependency is quite complex, it depends on the amount of degrees the text occupies in your field of vision, but also on the mode of reading you're in (very focused reading seems to narrow the fixation span). Also, please note that your eye makes constant micro-saccades (https://en.wikipedia.org/wiki/Microsaccade https://en.wikipedia.org/wiki/Microsaccade), and that the authors of the paper were probably compensating for these saccades as well, more or less. Quote from the actual paper This experiment has provided data which begin to answer the question about the size of the perceptual span during a fixation in reading. Although it may be possible in tasks other than reading for subjects to identify letters. word shapes, and word-length patterns some distance into the peripheral areas, in fluent reading this information appears to be obtained and used from a relatively narrow region. Thus. a theory of fluent reading need not suppose that word-shape and specific letter information is obtained from a region occupied by more than about three or four words during a fixation. and perhaps not that large if the span is not symmetrical around the point of central vision, a question not tested in the present study. Thus. it does not appear to be true that entire sentences are seen during a fixation; in fact. for most fixations. not even a complete phrase will lie within this area. So the "window" or "span" that needed to be un-masked was about 3-4 words wide (interestingly, this did not necessarily depend fully on the length of the words)

cooper12 11y ago

Your video reminded me of this selective attention test: https://www.youtube.com/watch?v=vJG698U2Mvo https://www.youtube.com/watch?v=vJG698U2Mvo. This Wikipedia article also seems to be related to the phenomenon and talks about the video too: https://en.wikipedia.org/wiki/Inattentional_blindness https://en.wikipedia.org/wiki/Inattentional_blindness.

Phemist 11y ago
Yes, this is always named in the same breath as my GP post, the gorilla video is a classic. The video I posted much the same thing. It makes you realise how much of what we perceive is really what we think we perceive

soared 11y ago

M$ research has AWESOME stuff on foveated graphics. They essentially track your eye movement and only render detail in the specific spot on the display you are looking out. Everything outside your eye's focus area is still rendered but a a much lower quality. Saves immense amounts of resources, imagine your gpu only having to render 20% of the screen at a time! http://research.microsoft.com/apps/pubs/default.aspx?id=176610 http://research.microsoft.com/apps/pubs/default.aspx?id=1766...

Phemist 11y ago
As an analog to lossy compression - lossy rendering?

danans 11y ago

There was an exhibit demonstrating a similar optical phenomenon in the Exploratorium (http://www.exploratorium.edu/ http://www.exploratorium.edu/) in San Francisco: The viewer watches a series of projected photographs of a streetscape with small differences between each (a pedestrian appears, a taxi disappears), but they don't see these changes because when the image changes, a small flash occurs, which somehow resets the optic system's change-detection system. The viewer can then press a button to suppress the interstitial flashes, and with no flashes, they can easily see the differences as they occur.

deleted 11y ago

[deleted]