[HN Gopher] Akiyoshi's Illusion Pages
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       Akiyoshi's Illusion Pages
        
       Author : robin_reala
       Score  : 288 points
       Date   : 2023-09-15 12:43 UTC (10 hours ago)
        
 (HTM) web link (www.ritsumei.ac.jp)
 (TXT) w3m dump (www.ritsumei.ac.jp)
        
       | xwdv wrote:
       | I wonder if any 8-bit era games used these kinds of illusions to
       | simulate advanced shader effects.
        
       | tempaway75751 wrote:
       | The most mind blowing optical illusion I've seen are Kokichi
       | Sugihara's Ambiguous Objects:
       | 
       | https://www.youtube.com/watch?v=KtA6u1HIqbg
        
         | nojs wrote:
         | A similar one that I like, and you can easily make yourself:
         | 
         | https://www.moillusions.com/dragon-illusion/
        
           | catbird wrote:
           | That was a fun little project. It looks even better in
           | person!
        
       | alberto_ol wrote:
       | Previous submissions, only the older ones have comments
       | 
       | https://hn.algolia.com/?q=Akiyoshi%E2%80%99s+Illusion+Pages+...
        
       | ayx wrote:
       | I can never see these illusions :/ Only the bulge works. Movement
       | I can't see at all.
       | 
       | Am I supposed to look at it a certain way? I tried at different
       | distances. I've tried using larger screens. Nothing..
        
         | pvg wrote:
         | A lot of the movement ones are more noticeable with actual
         | movement so scrolling a little bit could help. I notice them
         | popping more when I scroll through his twitter feed.
        
       | grilledchickenw wrote:
       | The second black hole one "Approaching black hole: yesterday" is
       | stunning. I cannot believe it's a still image.
       | http://www.psy.ritsumei.ac.jp/~akitaoka/saishin69e.html
        
         | Solvency wrote:
         | Am I alone in not understanding this black hole one... it's a
         | sequence of three obviously distinct still images in which the
         | black center is larger than the previous image.
         | 
         | Meanwhile, each image on its own is offering no kind of
         | perceptive illusion to me...
        
           | kazinator wrote:
           | I don't intuitively understand any illusion. I don't have
           | conscious introspection into what the layers of neurons are
           | doing between the retina and conscious visual perception. The
           | layers of neurons use certain indirect cues in order to
           | detect size, depth and movement. Those cues do their job in
           | most circumstances, but test cases can be constructed which
           | falsely trigger those cues. That's just an intellectual
           | generality that doesn't explain anything specific.
        
             | btilly wrote:
             | You should add shadow to the list of important cues.
             | Something light in shadow can be the same color as
             | something white in direct light. You can see that optical
             | illusion in
             | https://en.wikipedia.org/wiki/Checker_shadow_illusion.
             | 
             | My favorite example of where shadow matters is "the dress".
             | As https://slate.com/technology/2017/04/heres-why-people-
             | saw-th... explains, those whose brains assumed it was in
             | shadow saw it as white and gold. Those whose brains thought
             | it was in light saw it as blue and black. (It was actually
             | a blue and black dress, in light. But the photo was taken
             | in such a way that most people thought it was in shadow.)
        
           | tstrimple wrote:
           | For me it doesn't seem to grow. But the blurred edges
           | definitely show movement from my perception with both eyes
           | open. If I close one eye the effect goes away altogether.
        
           | gowld wrote:
           | The intent is that the black hole grows while you stare at
           | it.
           | 
           | Not all illusions work on everyone in every environment.
        
           | block_dagger wrote:
           | Staring at any of them individually makes the central circle
           | appear to grow. Bottom one is most effective for my eyes.
           | Creepy!
        
       | notsahil wrote:
       | Akiyoshi's twitter also has cool illusions:
       | 
       | - https://twitter.com/AkiyoshiKitaoka
       | 
       | - https://nitter.net/AkiyoshiKitaoka
        
         | bhtru wrote:
         | Nitter is dead no?
        
           | pbhjpbhj wrote:
           | It worked for me.
        
       | willmeyers wrote:
       | Can these affect your vision (long-term) if you stare at them for
       | too long? I feel like many of these images produce similar
       | effects to the McCollough effect.
       | https://en.wikipedia.org/wiki/McCollough_effect
        
         | JKCalhoun wrote:
         | When I was young (maybe 8 or so?) my mom got me a book of B&W
         | moire patterns. It consisted of a book of B&W patterns and a
         | clear plastic sheet also with similar patterns. When you
         | overlaid the plastic sheet over the patterns in the book is
         | when you got the moire patterns.
         | 
         | Besides seeing yellows and other _fringe colors_ appear from
         | the moire, I always wondered if the patterns were linked to
         | ocular migraines I would have for some decades after.
         | 
         | (Edit: yeah, this book: https://www.goodreads.com/book/show/244
         | 6119.Optical_Designs_...)
        
         | rqtwteye wrote:
         | I could imagine that it will change the way you perceive
         | things. There are experiments where people got goggles that
         | switched the left and right eyes and people adjusted after a
         | few days.
        
           | david422 wrote:
           | That's pretty wild.
        
           | davchana wrote:
           | Or even simple glasses which turn the view upside down. Human
           | eyes were able to adjust itself (or the image) correct way
           | after few hours.
        
             | d-lisp wrote:
             | I had a copy of some Merleau-Ponty work in which this
             | experiment was commented, IIRC the experimenter did really
             | think his brain was damaged when the world appeared upside
             | down to him without the glasses.
        
         | joshspankit wrote:
         | This is an interesting question and one that we're possibly
         | just on the leading edge of being able to ask correctly.
         | 
         | The answers are likely to be varied and along multiple axis:
         | 
         | - Do they affect the muscles of the eye, especially the ones
         | that affect the lens
         | 
         | - Do they affect the rods/cones (and do they equally affect
         | people with genetic differences)
         | 
         | - Do they affect the way the signals are sent to the brain
         | 
         | - Do they affect the visual cortex itself
         | 
         | and
         | 
         | - Do they affect the brain's processing of visual input in some
         | way
         | 
         | In my personal experience, I'd say we'd need to look at someone
         | for a minimum of 3 years, and ideally 5 or more.
        
       | dr_dshiv wrote:
       | My mind is blown.
       | 
       | I wonder whether the "Rauschenberg Illusion" would count. Named
       | after Robert Rauschenberg's blank white canvases which show that
       | big white fields are filled with illusions of color and form from
       | our visual system. (Or at least, they are for me. I'm not nuts,
       | am I?)
        
       | dang wrote:
       | Related:
       | 
       |  _Akiyoshi 's Illusion Pages_ -
       | https://news.ycombinator.com/item?id=25785081 - Jan 2021 (17
       | comments)
       | 
       |  _Akiyoshi 's Illusion Pages_ -
       | https://news.ycombinator.com/item?id=13793715 - March 2017 (32
       | comments)
       | 
       |  _Akiyoshi 's illusion pages_ -
       | https://news.ycombinator.com/item?id=5697783 - May 2013 (15
       | comments)
        
       | moritzwarhier wrote:
       | I was really happy about the first one, "spontaneously",
       | including the quotes, this is such an apt description!
       | 
       | Alas, for me it seems to occur mostly on eye movement/focus
       | change.. which happens to happen... spontaneously
        
       | fny wrote:
       | Are there rules for creating these illusions?
        
         | guyomes wrote:
         | Mark Changizi had an interesting insight on how some illusions
         | work [1].
         | 
         | What we see is a reconstruction by the brain interpolated from
         | our sensors. The idea of Mark is that the image is not only an
         | interpolation of the present, but actually also an
         | extrapolation of what the image will be in the next tenth of a
         | second. For tasks such as catching a ball, this would allow us
         | to compensate for the delay of the signal between our brain and
         | our muscles.
         | 
         | Based on this idea, he wrote a classification of many illusions
         | [2].
         | 
         | [1]: https://www.livescience.com/4950-key-optical-illusions-
         | disco...
         | 
         | [2]:
         | https://onlinelibrary.wiley.com/doi/full/10.1080/03640210802...
        
       | gowld wrote:
       | > Caution, continued
       | 
       | > Some of the pictures on this website can cause dizziness or
       | might possibly epileptic seizures. The latter happens when the
       | brain can't handle the conflicting information from your two
       | eyes. If you start feeling unwell when using this website,
       | immediately cover one eye with your hand and then leave the page.
       | Do not close your eyes because that can make the attack worse.
        
       | 3seashells wrote:
       | Persistent Visual cortex defects. Now imagine the brain riddled
       | with similar defects, when it's comes to reasoning and learning.
       | If there was one creature not defect, the whole rest of the zoo
       | would be sad.
        
       | lisper wrote:
       | It's possible to create "impossible" shapes in real life:
       | 
       | https://flownet.com/ron/trips/Europe2023/pause/206.html
        
         | gowld wrote:
         | 2D projections of 3D impossible shapes, yes.
        
       | kazinator wrote:
       | Some of the movement illusions really pop out if you slowly move
       | your finger across the image and track it with your eyes. Or use
       | a mouse pointer similarly if you're on desktop.
        
       | ceddec wrote:
       | A lot of graphic illusions are used commercially e.g for product
       | advertising like here: https://www.shapeshiftermedia.com
        
       | joshu wrote:
       | He posts regularly here: https://twitter.com/AkiyoshiKitaoka
        
       | aimor wrote:
       | This one almost hurts, forget the approaching black hole I get
       | dazzling speckles of white light. :
       | http://www.psy.ritsumei.ac.jp/~akitaoka/Plaid-tunnel02-040-b...
        
       | btilly wrote:
       | I used to have a high quality printout of the rotating snakes
       | illusion by my desk.
       | 
       | I had people who refused to be at my desk because it creeped them
       | out that they absolutely knew the paper couldn't be moving, but
       | their brains kept seeing the snakes rotate.
        
         | thanatos519 wrote:
         | What a great filter that must be!
        
       | susam wrote:
       | One of Akiyoshi Kitaoka's recent work that I found absolutely
       | stunning is the following illusion where a ring of one colour
       | appears to be either in front of or behind two rings of another
       | colour:
       | 
       | https://twitter.com/AkiyoshiKitaoka/status/16812686184854568...
       | 
       | https://nitter.net/AkiyoshiKitaoka/status/168126861848545689...
       | 
       | To my perception, the blue ring appears to float above the red
       | rings. It feels a bit like an autostereogram where a
       | 3-dimensional image emerges out of a 2-dimensional image.
       | However, there is no autostereogram in this image and there is no
       | crossing of eyes involved. The 3-dimensional image arises out of
       | an otherwise plain image of differently coloured rings on a dark
       | background.
       | 
       | An analysis of this illusion is available here:
       | http://www.psy.ritsumei.ac.jp/~akitaoka/Kitaoka2015_Referenc...
        
         | magic_hamster wrote:
         | That's a very cool illusion. First time I see it. I wonder if
         | the color patterns on the different rings have something to do
         | with it.
        
       | TeaDude wrote:
       | I'm very shocked that these were only discovered so recently
       | (Well. If you consider the early 2000's to be "recent". I'd have
       | assumed that we'd have found these out earlier)
       | 
       | I suppose that's why they were all the rage in childrens' books
       | and museums around that time.
        
         | [deleted]
        
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       (page generated 2023-09-15 23:00 UTC)