[visionlist] [cvnet] Trying to demonstrate stereoscopic vision remotely

Sat Mar 21 02:06:15 -04 2020

Thanks, Christopher!  I had listed random dot autosterograms as one option,
and noted, as you did, that many people unfortunately have great difficulty
learning to under-converge or over-converge.  However, your Scholarpedia
page is extremely informative.  I learned a lot from it.  I
(embarrassingly) hadn't realize the seminal role you played in the
development of the algorithms for them.  I'll probably give some
autostereograms to the students.  The students who manage to learn to
perceive them will enjoy them.

BTW, from an artistic point of view, some of my favorites are by Shiro
Nakayama, from the Super Stereogram books you mentioned.

Best wishes,

Les

On Fri, Mar 20, 2020 at 11:51 PM Christopher Tyler <cwtyler2020 at gmail.com>
wrote:

> You could try autostereograms, such as the examples on my Scholarpedia
> page <http://www.scholarpedia.org/article/Autostereogram>.  Not everyone
> can get them, but they're pretty effective for those who can.
>
> All the best,
> Christopher
>
> On Fri, Mar 20, 2020 at 9:35 PM Lester Loschky <loschky at ksu.edu> wrote:
>
>> Hi Everybody,
>>
>> If you teach Sensation and Perception, and are currently preparing to
>> teach it remotely, you may have the same question I have: how can you
>> demonstrate stereovision remotely?
>>
>> As preface, the following are methods I have used in in-person classes to
>> demonstrate stereo vision:
>>
>>    1. an actual stereoscope and example stereoimages to share with
>>    students (including the classic Julesz square tile random-dot-stereogram
>>    image)
>>    2. example stereoscopic lenticular lens images to share with students
>>    3. red/green anaglyph images with sets of cardboard & plastic
>>    red/green anaglyph glasses
>>    4. Google Cardboard plus cell phone to share with students
>>    5. random dot autosterographic images
>>    6. touching two pen tips together using two eyes versus one eye
>>    7. learning about crossed vs. uncrossed disparity using two fingers
>>    at different distances
>>
>> Unfortunately, my students don't uniformly have access to the apparatuses
>> required for 1-4 above.
>>
>> Re. # 3 (red/green anaglyph images), I've thought of having students
>> order a single pair of red/green anaglyph glasses online.  However, it
>> appears that the cardboard and plastic ones can only be purchased in bulk.
>> (I guess they're too cheap to sell individually.)  They also might not
>> arrive in time, but students could still enjoy them once they get them.
>>
>> Re. #4 (Google Cardboard), I recall getting a free Google Cardboard from
>> the NYTimes several years ago.  However, they are now no cheaper than $5
>> (Irisu, of India), and likely wouldn't arrive in time.
>>
>> Regarding option #5 (random-dot autostereograms), I have found that since
>> seeing random dot autostereographic images in depth requires perceptual
>> learning, a large proportion of students don't manage to learn (within the
>> short time period given in a single class period).  (Of course, many
>> students may have a lot of time on their hands now, so they might keep at
>> it long enough to learn to perceive them.  But there will definitely be a
>> good proportion of students who don't try long enough to learn, and so
>> don't get it.)
>>
>> #6 (touching two pen tips together) is definitely something that can be
>> done remotely.  However, it doesn't have the "Wow!" factor of other
>> demonstrations.  It is more of an "oh, really..." experience to realize how
>> much worse you are with one eye than two.
>>
>> #7 (using two fingers at different distances to teach crossed vs.
>> uncrossed disparity) can definitely be done remotely.  It is very
>> educational, but again does not have the "Wow" factor.
>>
>> There is also the finger "hot dog" illusion, which can be done remotely.
>> It is interesting, but quite different from all of the others in that
>> stereoscopic depth perception is not involved.
>>
>> For the related phenomenon of motion parallax, "wiggle vision" is a very
>> nice demonstration:
>> http://www.well.com/user/jimg/stereo/stereo_gate.html
>>
>> https://www.3dwiggle.com/2016/06/28/5-wigglegrams-you-need-to-see-before-you-die/
>>
>> Of course, depth perception from motion parallax is importantly
>> theoretically related to stereoscopic vision (both involve two different
>> images from two different views, one seen over time (and only needing one
>> eye)--motion parallax--and the other seen simultaneously (and requiring two
>> eyes)--stereovision).  But it is not the same as stereoscopic vision, so is
>> a separate but related issue.
>>
>> For the related phenomenon of binocular disparity, there is the famous
>> "hole in your hand" illusion using a cardboard paper towel roll.  If
>> students have a spare cardboard paper towel roll, they can do this
>> remotely.  But, again, it is a theoretically related but separate issue.
>>
>> Any other suggestions would be appreciated.
>>
>> Best wishes,
>>
>> Les
>> --
>> Lester Loschky
>> Professor
>> Associate Director, Cognitive and Neurobiological Approaches to
>> Plasticity Center
>> Department of Psychological Sciences
>> 471 Bluemont Hall
>> 1114 Mid-Campus Dr North
>> Kansas State University
>> Manhattan, KS  66506-5302
>> email: loschky at ksu.edu
>> research page: https://www.k-state.edu/psych/research/loschkylester.html
>> lab page: http://www.k-state.edu/psych/vcl/index.html
>>
>> _______________________________________________
>> cvnet mailing list
>> cvnet at lawton.ewind.com
>> https://lawton.ewind.com/mailman/listinfo/cvnet
>>
>

-- 
Lester Loschky
Professor
Associate Director, Cognitive and Neurobiological Approaches to Plasticity
Center
Department of Psychological Sciences
471 Bluemont Hall
1114 Mid-Campus Dr North
Kansas State University
Manhattan, KS  66506-5302
email: loschky at ksu.edu
research page: https://www.k-state.edu/psych/research/loschkylester.html
lab page: http://www.k-state.edu/psych/vcl/index.html
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