Talk:Autostereogram

Different types of autostereograms

We are trying to come to an agreement on various ways to classify and name different kinds of autostereograms. Please add your ideas in this section. Fred Hsu 02:03, 2 June 2006 (UTC)

Autostereograms

1. Text/ASCII Stereogram
 1.1 Text Floaters
 1.2 Hidden Image Text Stereogram
 1.3 Pop-up words Text Stereogram
2. SIRDS - Single Image Random Dot Stereogram
3. SITS - Single Image Textured Stereogram
 3.1 Unmapped Texture Stereogram
 3.2 Mapped Texture Stereogram
 3.3 Contour Stereograms
4. Array Object Stereogram
 4.1 Flat Objects Stereogram
 4.2 3D objects Stereogram
 4.3 Morphing objects Stereogram
 4.4 Solid Array Stereogram
 4.5 Cloud Stereograms
5. Vector Based Stereograms - http://torina.fe.uni-lj.si/~zlobec/sang/sang2.html

Description of each type:

1. Text/ASCII Stereogram A Text column either random or specific is used as a repeatable pattern. While Text Floaters (1.1) type shows same looking text areas at different levels of depth, a Hidden Image Text Stereogram (1.2) shows a relief scene. Because of discreet nature of positions of ASCII characters the 3D image always has limited number of layers.

2. SIRDS - Single Image Random Dot Stereogram. A dot with random color is used for all connected points (*explaining diagram needed) in a row. Number of levels of hidden relief scene is limited by a maximum number of pixels between maximum and minimum parallax.

3. SITS - Single Image Textured Stereogram A color image is used as a base pattern. Special algorithm copies the pattern with a horizontal shift which depends on relief of a hidden elevation(depth) map. Unmapped Texture Stereogram (3.1) is a most popular type of stereograms because of an ease of its production. Mapped Texture Stereogram (3.2) requires adjusting position and scale of the pattern along with creating specific texture which corresponds with hidden objects and their elements. Mapping allows to show details and desired colors on specific spots of hidden scene. Because of repeatable nature of Single Image Stereogram all connected points should look same, thus not all parts of hidden scene can have their own color. In other words one dot of the pattern will be assigned to many points in one row.

4. Array Object Stereogram These stereograms do not contain hidden image. They consist of an arrays of cloned objects distributed along horizontal line. The distance between objects (parallax) defines virtual level of depth on which the objects will be observed. Flat Objects Stereogram (4.1) uses array of same images which will look flat inside a stereogram. 3D Objects Stereogram (4.2) uses array of images that each one represents different view of virtual 3D object. Certain rotation of each image will reproduce stereoscopic relief of all objects in array. Morphing objects Stereogram (4.2) have an array of objects each one slightly differ from one next to it. Although it causes retinal rivalry this technique allows to vary object's color or shape in one array. Solid Array Stereogram (4.4) consists of 3D objects connected each to other. Instead of rotation a taper modifier is used to create stereoscopic effect and to preserve array's integrity.

See Relevant discussion in the 3D Stereogram Forum.

Unfinished tasks from peer review

Jan van Male

• These images are purely made for recreational purposes?
• Are there any limits on the size of the depicted objects?

.....

• Recreational: some people claim autostereograms actually help correct eye problems (assuming that you are using wall-eyed viewing). I think this may be true, but I haven't yet come across real evidence/literature on this. The two-image version (those viewed under stereoscope) actually helped the military discover camouflaged ground vehicles. But... err... yeah, they are mainly for recreation.
• Size: I am not sure what you mean by size. Is it the overal size of the hidden 3D image (that is, the physical dimension of the stereogram - A4, legal, poster size, etc.)? Do you mean the physical distance between the repeating patterns? These all depend on the viewing distance. I was able to see the autostereograms in this article projected on a 12-foot screen, but it required extreme eye divergence. It took me quite a while to master that. Another reviewer in the article discussion page also asked about this. I think I'll add a subsection on this.

• Recreational: Single Image Stereograms can be used where ever a stereoscopic presentation of clear relief needed in full screen. For instance - watching elevation maps in GIS (Geographic Information Systems) applications and results of electron microscope, previewing Objects in 3D modeling tools. But because not everybody can view Stereograms, they may be just useless. Also they (SIS) can be used for any purposes where hidden but readable information needed, like answers for a task, not annoying advertising messages, serial numbers and IDs. I would love to have a credit card with hidden number ;)

Older stuff

is that the only PD example you have? It's has extremely limited contrast for the square and will be hard for inexperianced people to image (it's also _small_) Rick Boatright 22:00, 16 Mar 2004 (UTC)

It's my first image upload and there's a lot of stuff about not making images too big, so I erred on the small side. All I've got is an un-cropped version. What do you mean by contrast? That the square doesn't 'jump out' enough? Please understand that these are time-consuming to make by hand, so if I'm to change it I need to know everything that's wrong with it. --rparle 22:08, Mar 16, 2004 (UTC)

Boy, I know they're time consuming to make by hand. I can't imagine. Ick. But here's the thing. Make a thumbnail with a caption of "too small to view for effect" and link to the full sized image. I _think_ that to get a reasonable "pop" you're going to have to approach 500 pixels wide.... There are times and places that a big image is appropriate. Rick Boatright 00:05, 17 Mar 2004 (UTC)

I've got a few skeletons of pictures lying around and I've got a pretty good idea of what I'm doing right and wrong with them, so I should be able to do one with better contrast and maybe (if we're lucky) a more interesting shape. I'd love to do the wikipedia logo, or at least it's silouette. --rparle 03:12, Mar 17, 2004 (UTC)

The one I've put up now is much higher contrast then the first. It's big enough to see pretty easily I think. --rparle 20:01, Mar 18, 2004 (UTC)

MUCH BETTER! Rick Boatright 05:57, 19 Mar 2004 (UTC)

Thanks for the help Rick, I'm pleased with the current image. It's nice to know that someone is actually seeing the work I've done. --rparle 16:30, Mar 19, 2004 (UTC)

I removed the following line because I had no clue what it was meant to say. If someone wants to clarify, be my guest:

The fact is that there is a clear limit on how much the eyes can go away from each other, it is when there are parallel : about 6 centimeters away.

--Rory ☺ 01:14, Jul 8, 2004 (UTC)

I added quite a few images and paragraphs. Due to server problem, I didn't edit my writing carefully. If anyone is interested in editing my writing, please go ahead. Also, I'll be adding more stuff to the "How To See Them" section in the near future. Fred 2005 Mar 7

Well, the first draft for this page is finished. The article now has expanded How Do They Work and How To See Them sections each with its own subsections. The next step is to expand History and Refererence sections. Fred Hsu 01:10, 13 Mar 2005 (UTC)

limitations

is there a publication of researh on the limitation? i.e. to what extend this method can create illusion of 3D? For example, apparently it can only emulate surfaces, i.e. the viewing angle is only some 20 degrees. For fine can the 3d object illusion be achieved? e.g. can it emulate a mesh of wire? is it possible to extend this method to include color? ... Xah Lee 19:00, 2005 Feb 6 (UTC)

I added a dozen of examples to illustrate some of the issues you brought up. Due to wikipedia server problems, the editing process took 5 times longer than it would have under normal conditions. But this is my first wikipedia editing... perhaps this is the norm :( I will add more paragraphs in the future to address other questions. For instance, the limit for the perceived depth of image is the distance between repeated patters. The limit for the resolution of depth is the physical size of each pixel. Fred 2005 Mar 7

Temporarily removed content

I am replacing this image with a color random dot stereogram showing the same shark used in other illustrations in this article. I don't want to lose the original image. So I moved it here temporarily. Fred Hsu 04:22, 14 Mar 2005 (UTC)

This example is a random dot stereogram featuring a two raised boxes on a flat background. The boxes appear closer than the background because the distance between repeats on the squares is ten pixels shorter than on the background.

On this one I sometimes see two boxes floating in front of two floating rectangles. --Gbleem 04:03, 8 September 2006 (UTC)

Yes, it is possible to see towers of blocks 2, 3, and 4 levels high - I haven't managed 5 yet. Is the general mechanism for this mentioned in the article? -Tim Rawlinson 12:38, 8 September 2006 (UTC)

This will happen when you end up focusing your eyes on images that are more than one texture width apart (call it N textures). Since the way you position the random pixels repeats across the image, you see the changes in depth echoed across the image by the same number N of texture widths apart you are viewing the image. Note this description works for any value of N even zero or minus one where you are viewing cross eyed. —Preceding unsigned comment added by 219.90.216.168 (talk) 13:39, 9 April 2008 (UTC)

Image size

The example images on this article are display small enough on the screen I'm using today that they are difficult to view, on Magic Eye's old scale I would say they require advanced technique. They could be a maximum of 550 pixels wide per Wikipedia:Image use policy#Displayed image size. On this monitor that only creates line breaks in the "3 Mechanisms for viewing" subheadings on the table of contents. I propose that we display the images at maximum size for ease of viewing and additioinally that we shorten those subsection headings to "3D perception" "Creating/Simulation/? 3D perception" and "Tips". Hyacinth 05:40, 1 June 2006 (UTC)

The reduced versions of images are not really meant to be "viewed" as displayed. As it stands, people already complain about number of images in this article compared the length of text (it's quite abnormal by wiki standard). If every image is displayed full size in place, the article will look really awful. I hope people click on images they find interesting to see it full-size... Fred Hsu 01:38, 2 June 2006 (UTC)

I just renamed the 3 subsections. Thanks for the suggestions. Fred Hsu 01:44, 2 June 2006 (UTC)

I restored the lead picture to standard lead image size. See how people don't use big images even on articles on paintings: The Last Supper (Leonardo). Also notice that I added "click on thumbnail to see full-size image" on the image description. I think it is common practice to use thumbnail images and rely on readers to click on them: Wikipedia:Picture_tutorial#Resizing.

This is not the same thing. I can see the large details of The Last Supper in the thumbnail (guys around a long table) while most users would not be able to see the one large figure in Image:Stereogram Tut Random Dot Shark.png. Hyacinth 21:35, 6 June 2006 (UTC)

But users can see it is an autostereogram, and that this is what they look like. If they want to invest the time and effort to see the image, they can click on it as clearly indicated in the caption. Skittle 22:24, 6 June 2006 (UTC)

This is a Good Article

After reviewing the article, I've determined it to meet the qualifications for Good Article status. It's a nice piece of work, and its clear that the authors have gone to great lengths to aquire books for references. I can tell its come a long way with the FA/N and the peer review, and things are well within GA levels.

I don't have many specific comments for further improvement at the moment, however, continued work in image sizing and positioning for good viewing in all browsers would be recommended. I'm viewing in an 8x6 Firefox window, default skin, and while things look good for the most part, there is a little overlapping in the Simple Wallpaper section. Nothing bad, but its worth continued tweaking, and testing in various window sizes and browsers.

If you desire more clarification on my reasoning for promotion, just leave me a message on my talk page. Good work, everyone! Phidauex 15:45, 29 June 2006 (UTC)

• I haven't experimented further with image size/placement after the article was rewritten. But at that time, it was very hard to make images look OK for all situations. The main problem was the sheer number of images accompanying short paragraphs. I will give it another try in the future. Fred Hsu 00:45, 30 June 2006 (UTC)

• And, thanks to everyone for your suggestions, reviews and promotion. Fred Hsu 00:45, 30 June 2006 (UTC)

Creating Autosterograms

Is there a way to create a Autostereogram on your computer? Or turn a image you have into a Autostereogram? Caleb09 00:09, 8 September 2006 (UTC)

Just search for autostereogram software on goggle. There are quite a few free programs you can download. I wrote my own after I figured out how autostereograms work. But it is too crude and specialized that I don't want to make it available to unsuspecting public. You can also head over to the 3D Single Image Stereogram discussion group. There is a Links page to lots of autostereogram sites (images and software). But you need to join the group first. Fred Hsu 00:30, 8 September 2006 (UTC)

Regain stereo vision

I have amblyopia and I have always been able to see these types of images. Am I some kind of medical weirdo? Jcsavestheday (talk) 05:21, 19 February 2009 (UTC)jcsavestheday

I know I heard a story on the radio about a woman who regained her stereo vision on our local public radio station. Not sure what program. --Gbleem 03:40, 8 September 2006 (UTC)

I found it. NPR story --Gbleem 03:58, 8 September 2006 (UTC)

• Yes, I heard this one on WNYC as well. Needless to say, I captured my attention right away. But I am not sure if this is a one-off miracle that happens to 1 in million people with amblyopia, or a real, new medical fact. I'll follow up on this. Fred Hsu 08:54, 8 September 2006 (UTC)

Wonder if it is true that you can only lack this ability to see what is not there, if your eyes are bad(..how bad?) when ur a kid. Perhaps i should start staring half hours at these pics? I anyhow dont have lazy eyes, or lack off stereoscopic vision (there is a whole lot of difference for me watching the real 3d world from watching flat pictures) However i am shortsighted all my life, is that the answer? Can't help but being curious to know wether i would see the effect when i trie for more then halfhours.80.57.242.54 07:34, 8 September 2006 (UTC)

• You need stereopsis in order to see autostereograms. But stereopsis is only one of the many mechanisms used by the brain to reconstruct stereo shapes (binocular vision). What you experience as 3D vision may in fact some from other visual cues. There is a simple way to check. Get yourself a stereoscope and see if you can see 3D images. If you can, then you will eventuall be able to train yourself to see autostereograms. Fred Hsu 08:54, 8 September 2006 (UTC)

So the head should be: regain stereoptic vision. I tried stereoscope, i think, it must have worked. However probably i underdeveloped the issue wich having to do so much with contours only makes sense. As a child already i thought intelligence was helped by shortsightedness (sublimalisation of essentials) , and tiring of stereoscopic experiments indeed (rea)points to human's visual intelligence. more stereopsis feels nice(pretty), but when the gorilla has to choose between a banana and an office-job:)(80.57.242.54 09:23, 9 September 2006 (UTC))

Plane

The caption for Image:Stereogram_Tut_Clean.png says "The illusion of a plane lying behind the wall is created by the brain." I was expecting to see an aeroplane rather than a plane (mathematics). --Henrygb 08:40, 8 September 2006 (UTC)

• Yes, if a new reader first looks through images/captions in the article, the word "plane" can indeed be mistaken for "aeroplane". I added "(flat surface)" to that caption, for now. Fred Hsu 09:02, 8 September 2006 (UTC)

Accidental Stereogram

I merged this into the Animated section for the time being. I can't verify this at the moment as I do not have access to CRT monitors. But I'll verify this later today. 09:20, 8 September 2006 (UTC)

It's quite an informative article, I feel.

Well Done

Well done to all in getting this to FA standard and on the main page. I still think it's one of the best articles I've ever seen on Wikipedia. Skittle 11:41, 8 September 2006 (UTC)

Dittos on that. A very interesting and informative article. Many thanks to all the collaborators! Erzahler 21:34, 8 September 2006 (UTC)

I just want to say that I think this is the best article I have ever read on Wikipedia, and I am a heavy user of the site. It gives a clear step-by-step explanation to a fascinating subject. Well done to all who were involved in its creation - you guys deserve some serious credit. 81.148.252.51 (talk) 21:44, 25 August 2010 (UTC)

Autostereogram reversing program?

I know there are computer programs to change images into autostereograms, but is there a program to take an autostereogram, analyze the image and the repetition within, and output what it's supposed to show a person (so that a person, for instance, with an eye problem, could see the image)?

Also, was my question stated clear enough so that you could understand it? (some people have trouble understanding the way I ask questions)

• Very clear. I have thought about writing such program myself. It is not as easy as producing one. The brain is truly an incredible organ. But yes, it can be done, and perhaps someone has already done that... Fred Hsu 14:03, 8 September 2006 (UTC)

Check out this website! It runs a Flash application. You can paste an URL to an autostereogram JPG, and adjust the Focus slider (you may need to page up to see the two sliders) until you see the hidden 3D shape, without using stereopsis. You can use one of the 5 built-in jpg files, or try "http://www.fred-hsu.com/game/Stereogram_Tut_Shark.jpg" and move the Focus slider to the right (about 1/4 from the right). Fred Hsu 03:28, 29 September 2006 (UTC)

This site from the same author allows you to construct URL with your own image and focus factor. php version Fred Hsu 06:07, 6 October 2006 (UTC)

Introductory sentence

The introductory sentence currently reads: "An autostereogram is a single-image stereogram (SIS), designed to trick human eyes and brains into seeing a three-dimensional (3D) scene in a two-dimensional image." As the "How they work" section explains, stereopsis occurs in the brain not in the eye. The eyes are not "tricked" as they just gather information. -AED 15:31, 8 September 2006 (UTC)

• Thank you very much for helping to make this article better. Fred Hsu 23:20, 8 September 2006 (UTC)

this article doesn't make the slightest sense

boooh!

It's a schooner! --Bobak 17:07, 8 September 2006 (UTC)

Very cool

• Well written article on a cool subject. Great pick for the front page. Props to everyone involved in writing this. Wickethewok 18:24, 8 September 2006 (UTC)

Image placement

I temporarily removed these two changes. Image placement in this article is pretty tricky (see comments in Peer review and feature article candidate pages). After today's flurry of activities die down, we should reconsider image placement again.

• 15:34, September 8, 2006 Celardore (Talk | contribs) (→Random-dot - Removed image that is already in the header of the article.)
• 15:30, September 8, 2006 Orayzio (Talk | contribs) m (→Simple wallpaper - fix image overlap)

Viewing tips for this article

• Keep trying with the reduced-size images, as they require less eye movement than the full-sized images. I can only see the full-size images cross-eyed. Gazpacho 22:08, 8 September 2006 (UTC)
• Adjust your monitor so that the screen is perpendicular to your line of sight. Gazpacho 22:08, 8 September 2006 (UTC)

Will incorporate these into the article soon. Fred Hsu 23:18, 8 September 2006 (UTC)

Good sentence structure?

"In order to perceive 3D shapes in these autostereograms, the brain must decouple focusing operations of the eyes from convergence."

This quotation from the introduction of the page sounds as though it is grammatically incorrect, but I'm not sure if some of the terms are technical terms that I just don't understand.

Please take a look at it.

Thanks. —The preceding unsigned comment was added by Mikerobe007 (talk • contribs) .

It looks fine to me. Here's how I parse it: (In order to perceive 3D shapes (in these autostereograms),) the brain must decouple ((focusing operations) of the eyes) from (convergence). —Keenan Pepper 02:11, 9 September 2006 (UTC)

Hey, Keenan, in a few days, I'll try to make sense of all new stuff added into this article, and do a first round of copyediting. I'll ask you to proofread one more time when I am done, if you don't mind. Hopefully, wiki's built-in diff will be good enough to allow you to quickly look at new changes. I've noticed that when a paragraph is split into two, the diffing process gets really confused. Fred Hsu 04:10, 9 September 2006 (UTC)

Sure, no problem. —Keenan Pepper 18:32, 9 September 2006 (UTC)

Update definition of Stereopsis?

The current definition, while not incorrect, could be improved upon by mentioning that the differing images have to be presented to differing eyes. While this is mentioned elsewhere in the article, readers parsing the article looking for a brief overview may fail to realise the importantance of binocularity upon reading this definition.

Fillup 00:04, 18 January 2007 (UTC)

Color blindness

I didn't find any information in the article about if autostereograms "work" for people who may be afflicted with one of the various types of color blindness. Does anyone have any good information to add on this topic? I think it would be appropriate to document in the article if so. Thanks. --V3rt1g0 03:21, 14 February 2007 (UTC)

Autostereogram does not rely on color. In fact, on this very same talk page (scroll up), you will find a black and white autostereogram. Autostereogram only rely on stereopsis. Remember, the hidden shapes appear colorless to a viewer regardless of the actual color of patterns in the autosteregram. The hidden shapes are revealed as depth changes. Let me go back to the reference books to see if I can dig up some paragraphs to support this, and I'll enhance the article. Also, my limited empirical observations based on only a few cases seems to indicate that often color blindness goes with amblyopia. Now, this is just my own speculation and is not based on any research or reference books at all. Fred Hsu 05:54, 14 February 2007 (UTC)

Interesting. Even if you end up not finding anything with enough officialness for the main article, I appreciate your answer here all the same. Thank you Fred Hsu. --V3rt1g0 16:40, 15 February 2007 (UTC)

Online discussion group on SIS

According to official policy, links to forums are not allowed, even if the topic of the forum is on the topic of the article itself. I know from my own experience that the yahoo forum on autostereogram is excellent. Members of this forum mail brilliant home-made autostereograms to other members of the group on a daily basis. If you are interested in autostereogram, you definitely need to sign up. But people keep adding this link to the article, and it keeps getting removed. I think it is time we create a section on this talk page to explain why such links are not officially allowed. Fred Hsu 00:53, 24 February 2007 (UTC)

Bibliophgraphy

Someone keeps adding two books in German to the Reference section. I removed them twice, but it keeps getting added back in badly formatted fashion (latest attempt by User:U7born. I don't know German, but the sentence appears to be German. I am moving this reference to the talk page for now (see below). I just bought these books from Amazon/Used as it appears to be out of print. If the book contains information not already discussed in the article, I'll add properly formatted reference back to the article. There are many good autostereogram books out there, including a few by friends of mine. They are not listed here because wikipedia is not a book store or a catalog all books. Besides, the book seems to be written in German as well. Fred Hsu 23:32, 19 May 2007 (UTC)

• Interactive Pictures ,Volume I und II , Panvision ,Design - Ulli Siebenborn , Taschen Verlag ,ISBN 3822892114 und ISBN 3822888524

Statistics on how many people can see them

I happen to be among the group of people who is unable to see these things - I've stared for hours at the books, computer images, etc., and I've never once gotten one of these things to work. I have pretty good vision, never needed glasses, never been diagnosed with lazy-eye or anything like that, and I have generally good spacial perception - I'm a 3D modeller for a living. But for some reason, these things just don't work for me. I'd be interested to see some statistics on how many people are able to view these things. I wonder if it's genetic, like rolling your tongue or something. Neither of my parents are able to see them either, and one of my two brothers also can't. (The other one claims to see them, though I'm tempted to call Emperor's New Clothes on him - I've actually always jokingly suspected this whole concept was a widespread hoax, and everybody just pretends to see them in order to annoy those who can't, but I'm not quite THAT much of a conspiracy theorist.) Lurlock 20:30, 21 May 2007 (UTC)

That's a really good question, and it's hard to find out the answer, or so I've found. I have data for people who can't achieve binocular fusion at all (ie, not even with a stereoscope), and the consensus seems to be that it's less than 1% of the population. Unfortunately, I don't have my MA research materials to hand, so I can't give you citations straight off, but the figure 0.7% seems to be lodged in my mind :)

It's actually extremely interesting to me that you mention that you're a 3D modeller. I was actually doing research, before my disability prevented me from continuing, on whether there's a differential occurrence of astereopsia between 3D designers and the standard population - it started from a conjecture that people with astereopsia may make better 3D designers because they have to rely on mental manipulations to inhabit a world without depth perception. Alas, I have no usable data on this :( but I'm still very interested in the idea. Kay Dekker (talk) 19:02, 2 September 2008 (UTC)

so, I might not be able to see them??? Boredom Swells (talk) 06:41, 3 January 2009 (UTC)

Temporarily removed Notable References

I removed the newly added section. The phrases need to be reworked. And inline citation added. Fred Hsu 03:35, 16 September 2007 (UTC)

Notable references in pop culture

Autostereograms were featured in the Seinfeld episode titled "The Gymnast." George's girlfriend had one in her bathroom. Also there was one in the office of Elaine's boss, Justin Pitt. This one contained a spaceship, which everyone culd see except Mr. Pitt.

An autosterogram showing a sailboat was also featured in Mallrats. Everyone could see it except Willam. Willam eventually did see it.

Convergence micropsia

I reverted the addition of Convergence micropsia to a new See Also section. It is not clear whether such phenomenon is a better explanation than foreshortening which is already mentioned in this article. Since there is no citation on the convergence micropsia page, I did a preliminary searching. I found this one for instance. It seems to imply that the apparent size reduction of objects is an adaptive strategy of the brain in an effort to maintain "size constancy". This is entirely different from the foreshortening explanation (in this article) for the 3 rows of cubes which appear with different apparent size.

Until the convergence micropsia article is properly cited, I think we should refrain from adding it here. And if eventually we do, we should add it to the 3-rows-of-cube paragraph, not to a See Also section. Fred Hsu (talk) 03:04, 3 April 2008 (UTC)

Dear Fred, Thanks for the prompt to add some citations to the article on convergence micropsia. The explanation is so old, and so well-accepted, that it is difficult to find modern references for it. I've found a few. I note that your explanation, foreshortening, is not referenced either. References would be a good idea because I do not understand the foreshortening explanation. It seems to depend on linear perspective, yet in random-dot autostereograms, no objects are seen until the depth objects are perceived. And those objects need not be rectilinear or have any parallel lines. In fact, foreshortening is not so much an explanation as simply a description of a technique of illustration to produce realistic 2D drawings of 3D objects.

I could not see the reference you cited for CM (I guess you must have a printed copy of the book), but it sounds approximately correct. That is, CM is consistent with the size-distance invariance hypothesis, with the geometry of space. The key issue is whether foreshortening has anything to do with perceived size in autostereograms.

I put back CM into a See also. But I agree with you that the explanation should go in the article itself. I'll leave it to you to convince yourself that it is a better explanation than foreshortening.

You'll see that I made a few changes to the article, mainly to cast it into standard English, to treat all named persons equally, and to purge it of any mention of the brain accomplishing perception. If you doubt the error of this latter, please read: Bennett, M. R., & Hacker, P. M. S. (2001). Perception and memory in neuroscience: A conceptual analysis. Progress in Neurobiology, 65, 499-543.

I also corrected the explanation of the wallpaper effect and made the use of wall-eyed and cross-eyed consistent throughout the article. I must confess I found the article too long and to contain a lot of redundancy, but I did not have time to deal with these issues.

Oh, and thanks for using your real name and for showing your pic. It's nice to know whom one is dealing with. Cheers! Robert P. O'Shea (talk) 10:52, 3 April 2008 (UTC)

No, I do not have any book that talks about CM as far as I remember. The one I cited was simply returned by this google search. At least with the one I cited, you can read the actual text. Your recent citations all contain just abstract.

I do have all books I added to the autostereogram article.

I have to admit that I was not happy when I saw your partial changes this morning. Many sentences seemed hastily added. Considering that this is a featured article, I thought that was not very professional. Now I realize you were in the middle of editing the article at that time. I will take a closer look at these changes.

I do not agree with your purge of any mention of the brain. If the brain isn't processing stereo images and constructing Cyclopean images, what is? Making sentences passive or substituting 'brain' with 'person' is not addressing the issue. Fred Hsu (talk) 03:24, 4 April 2008 (UTC)

I see. I followed up on my google search and indeed find both articles you added. Here is one with summary. Here is another one which may be useful. If I am reading these correctly, it is deemed that convergence plays a much bigger role than accommodation in reduction of apparent object sizes, even though the brain could have used both vergence (moving eyeballs) and focusing (accommodation) to gauge distance of object, thus using the ratio between measured retina size and distance to arrive at an apparent size.

This is completely in accordance with what has been described in books cited in this article, even though I do not remember authors mentioning this particular term. The key to viewing of autostereogram is the decoupling of vergence from accommodation, resulting in the brain using vergence alone to estimate distance of the repeated patterns, thus tricking itself into perceiving these patterns at different depth, thus with different apparent sizes.

So, I pulled out the "Foundation of Cyclopean Perception" by Julesz. The index shows one entry for 'micropsia'. It's on p300 and talks about miropsia together with macropsia and dysmegalopsia under influence of drugs.

I am still not convinced that the usual perception of depth and apparent object size is called "micropsia". Note that google only returns 77 hits for "convergence micropsia". I would expect a well-known term describing one of the most studied visual perception topic to yield more hists. I have always thought that this mechanism of stereopsis is known in arts as foreshortening which may mean several things. The most common usage of foreshortening is really just a synonyms for perspecive. Notice how "foreshortening" returns 400,000 google hits. Fred Hsu (talk) 03:56, 4 April 2008 (UTC)

However, if CM indeed describes the normal perception of object size based on vergence angle, then this is great news, as I can add many more references to various parts of the article which talks about binocular vision. Fred Hsu (talk) 04:08, 4 April 2008 (UTC)

On p148 of Julesz' book, he in fact mentions vergence and Emmert's law. On p176 there is a long discussion on the role of convergence on binocular depth perception, and on size constancy during symmetric (disjunctive as opposed to conjugate, parallel eye rotation) eye-movement. On p224 he mentions Kaufman and Rock (1962). I need to read these more carefully again. In fact, I should add more inline references at various paragraphs to this book. Fred Hsu (talk) 04:25, 4 April 2008 (UTC)

Well, Bennett's book can be accessed here. Apparently he claims that visual perception is not done in the brain (from my 10 minute perusal). This is a controversial claim. I can't believe you rewrote this article based on this to purge any mention of the brain's participation in visual perception. I am sorely tempted to revert all your changes, then reapply the good edits later. Fred Hsu (talk) 05:20, 4 April 2008 (UTC)

Review of recent major changes

User:Robert P. O'Shea has made extensive changes to this article. I like most of these changes, but I would like to edit them further. Here are some of the things I plan to do:

• The lead section is now too long. This is a summary section. And it should remain a summary of the article
• I would restore the previous wordings that refer to the "brain" as opposed to "the person" or some unnamed agent doing the visual calculations. Robert, please first edit Visual perception and Optical illusion to eliminate any mention of the brain and offer alternative explanations. Then we'll remove 'brain' from this article.

I thought I would give you a chance to include my changes you liked before I commented. But I suspect this is a class of changes you will not accept. Unfortunately you misunderstand the error involved in saying something like, "the brain tricks itself". Such a statement, and your reasoning about it, are erroneous for at least four reasons.

First, the statement makes no sense logically. I can trick someone else. That means I know something is true, yet I do something to make someone else know it is false. Could I trick myself? No. Because that would require that I both know that something is true yet know it is false. This is impossible.

Second, the statement involves the logical error mentioned by Bennet and Hacker. If you do not think it is an error, perhaps you can explain why. That will involve reading the paper I cited, rather than reading something on the web for 10 minutes.

Third, you have interpreted the error to mean that I am saying that the processing underlying our experience does not (largely) occur in the brain. This is incorrect too. Of course it largely occurs in the brain. This does not mean it is correct to say things like, "the brain must overcome [its normal processes]" or "allowing the brain to reconstruct [something]". These are still erroneous for the reasons Bennet and Hacker give.

Fourth, your challenge for me to rectify other articles that you allege make the same error is to claim that other errors make your error correct. It's to claim that two wrongs make a right. I have looked at the article on Visual Perception. It does not commit the error. The article on Optical Illusions does, but it commits numerous other errors--too many for me even to contemplate trying to rectify all of them. This is no reason for you to propogate the error in this article. Robert P. O'Shea (talk) 06:02, 7 April 2008 (UTC)

Let's take this slow. I will try to merge your other ideas in the article slowly over this coming week. I am very busy in real life at this moment, but I will give it my best try. I will also check out your Bennet and Hacker reference. I'll buy it if I have to.

But, why isn't Bennet and Hacker reference in other, more relevant wikipedia articles? Perhaps it is, if you can help me find them, that's would really help. Perhaps you can summarize the big picture for me and others to help us understand what exactly is wrong with describing the autostereograms (and in general, other optical illusions) as tricking the brain into perceiving fake scenes from images its naturally-selected faculties is ill-prepared to handle. There is a reason the phenomenon is called an 'illusion'.

At one point, someone in the autostereogram forum convinced me to read The Holographic Universe from Michael Talbot in order to "understand" why everyone else in the visual perception field was wrong. I actually bought a copy from Amazon. The book was such a crap I don't even know how to begin to describe why it is wrong.Fred Hsu (talk) 14:32, 7 April 2008 (UTC)

• I would remove the new See Also section with one reference to convergence micropsia. I will research this topic some more and once we come to a conclusion on this talk page, CM will be re-integrated back into the article into proper sections/paragraphs.
• I would restore parts of the History section. In particular, the discussion on Juleszs neurological explanation for binocular perception. Perhaps I will follow up on the Bennett 2001 mentioned by Robert first, to make sure I am not missing something obvious here.
• I will simplify some newly added phrases in the History section. These are described in oher sections in the article. After all, it's a history section.
• Changing 'visible' in various places back to 'apparent'.
• Add more inline references to Julesz' book. Mention Emmert's law, disjunctive eye movement, etc.

Robert, I wish you had discussed your changes first on the talk page. Fred Hsu (talk) 05:00, 4 April 2008 (UTC)

As a reference, this is the combined edits done so far by Robert. Fred Hsu (talk) 05:12, 4 April 2008 (UTC)

At this time, after reviewing all changes and research relevant topics, I feel I should revert the article back to its previous state, then reapply non-controversial changes from Robert back. After we come to agreement on controversial topics, we can add back more. We have full history, so it shouldn't be hard to re-apply changes. I plan to do this tomorrow. Fred Hsu (talk) 05:31, 4 April 2008 (UTC)

I waited a day in give Robert a chance to response. I have now reverted the article to its previous state. I'll selectively add back good changes by Robert today and tomorrow. Please provide proper, mainstream evidence that the 'brain' isn't doing the visualization before we prune the word 'brain' against from the article. And please remove all current citations from the article and provide your new citations in their place, as all of them refer to the brain as being tricked by the man-made patterns. Fred Hsu (talk) 15:07, 5 April 2008 (UTC)

On Bennett and Hacker and the Philosophical Foundations of Neuroscience

So, I was about to buy the Bennett and Hacker article for $31 dollar, when I thought, "may be I'll first check if the guy published a book or two". What do you know, there is Philosophical Foundations of Neuroscience at Amazon.com. I figure I would get a better picture of their positions by reading a complete book for $40. I was about to hit the one-click button, when I made the mistake of checking out reader comments first. It is clear from both positive comments and negative comments that the authors are simply playing language tricks that philosophers have long been employing. Check out reader comments.

Philosophy has no place in an article on autostereogram and visual perception. The authors seem to claim that brains are just cells. Brains cannot "perceive". It's the "mind" which does the perceiving. Or the "person" who does the perceiving. This is simply complete BS. Our mind is nothing more than the signals running across synaptic connections. Robert, you should check out Pinker's How The Mind Works if you really want to understand how the mind works. Fred Hsu (talk) 03:24, 8 April 2008 (UTC)

Extra Space After ==Random-dot==

Please remove it. I don't know how, thanks. It's extra space and unncessary and redundant and goes against MOS. If you have counter arguments, please notify me on my talk page, thanks. I don't know how, thanks.68.148.164.166 (talk) 07:22, 15 May 2008 (UTC)

I disagree about the "auto" part for some of these

Some of the so-called autostereograms are nothing but horizontal repetitions of small two-image stereograms!

How can you call this an autostereogram?

The objects that appear three-dimensional are formed by overlapping two completely separate little images (e.g. dophins etc). How can that possibly count as a different category of stereogram from a regular two-image stereogram?

Look, you can cover up everything else in that image except two adjacent dolphins, and yet still fuse the dolphins to see the image. Are these two dolphins an autostereogram? If not, why is the whole thing an autostereogram?

A true autostereogram should be defined as an image that produces a 3D illusion from overlapping data.

For instance, a 200 pixel 3D object is encoded, in say, a 300 pixel wide image, requiring a 10 pixel offset between the eyes, would be an example of an autostereogram.

The "auto" means that the shift between the eyes is smaller than the object that is perceived, so in effect a single 2D image encodes the two separate channels for the two eyes, which are decoded by the brain when suitably offset.

If there are two images, then there is no such encoding going on. A separate image is going into each eye. Hence, no shift encoding is taking place, and there is no autostereogram. —Preceding unsigned comment added by 192.139.122.66 (talk) 20:04, 17 December 2008 (UTC)

Medical conditions do not permit viewing

A significant proportion of the populace are simply unable to view these 3D posters because of physical inability to do so, through no fault of their own. I'm surprised the article doesn't even hint at that. A quick google search doesn't turn up the name of the condition or even a decent reference but I know that I've seen reference to this before - hopefully someone else can complete this article - those that "just don't get it" shouldn't feel bad, as there are people who legitimately will never be able to see these no matter what they do.198.161.2.241 (talk) 22:04, 7 January 2009 (UTC)

See my discussion under "Statistics on how many people can see them" above. I've a nagging feeling that it's discussed in one of Richard Gregory's books, but my active involvement with the subject ended a decade or so ago and time has wrought its usual blurring effect :( Kay Dekker (talk) 00:00, 29 May 2009 (UTC)

search for "amblyopia" in the article itself. Perhaps there should be a separate section dedicated to this. Fred Hsu (talk) 01:57, 29 May 2009 (UTC)

I don't think amblyopia has much to do with this. I don't have amblyopia, and I've never been able to see anything but a headache with these things. 72.83.179.77 (talk) 21:20, 28 November 2010 (UTC)

Example code in PHP

Moved code added by User:Deepmath from main article to talk page. Please keep in mind that this article is a Featured Article. While your program is a valuable piece of information (I am a programmer myself), adding it in raw code form to the article does not help most readers. Perhaps you should host your software and demonstration somewhere online and add a link to it on the External Links section. Fred Hsu (talk) 02:49, 15 August 2009 (UTC)

<?php 
// PHP Stereogram Generator v. 0.1
// Copyright (c) 2008-2009 User:Deepmath

// This program is free software.  Anyone may use, modify, and/or
// distribute this program freely without any restrictions whatsoever.

// By all means:
// Use this program to develop your own commercial application
// or your own art.  There is no requirement for attribution. 

function getimage($filename, $type) {
	switch ($type):
	case 'png':
		$im = @imagecreatefrompng($filename);
		break;
	case 'gif':
		$im = @imagecreatefromgif($filename);
		break;
	case 'jpeg':
		$im = @imagecreatefromjpeg($filename);
		break;
	default:
		$im = '';
	endswitch;
	return $im;
}

function returnimage($im, $type) {
	switch ($type):
	default:
	case 'png':
		header('Content-type: image/png');
		imagepng($im);
		break;
	case 'gif':
		header('Content-type: image/gif');
		imagegif($im);
		break;
	case 'jpeg':
		header('Content-type: image/jpeg');
		imagejpeg($im);
	endswitch;
}

function grayvalue($pixelcolor) {
	return	( ($pixelcolor & 255)
		+ (($pixelcolor >> 8) & 255)
		+ (($pixelcolor >> 16) & 255) )
			/
			765.0;
}

function findoffset($im, $map, $x0, $row, $patternwidth, $arf, $direction) {
	$offset = $patternwidth - (int)($arf * $patternwidth);
	for (;; $offset++):
		$x1 = $x0 + $offset * $direction;
		$xmap = ($x0 + $x1 - $patternwidth) >> 1;
		$graytarget = grayvalue(imagecolorat($map, $xmap, $row));
		$graytest = ($patternwidth - $offset)
					/
				($patternwidth * $arf);
		if ($graytest <= $graytarget) return $x1;
	endfor;
}
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
  set_time_limit(300);

  $pattern = getimage($_FILES['pattern']['tmp_name'], $_POST['patterntype'])
	or die('Bad pattern file');
  $map = getimage($_FILES['map']['tmp_name'], $_POST['maptype'])
	or die('Bad map file');
  $arf = (float) $_POST['arf'];

  $patternwidth = imagesx($pattern);
  $patternheight = imagesy($pattern);
  $mapwidth = imagesx($map);

  if ($patternwidth >= $mapwidth) die ('Pattern too wide');

  $width = $mapwidth + $patternwidth;
  $height = imagesy($map);

  $im = imagecreatetruecolor($width, $height);

  $minpatternwidth = $patternwidth - $patternwidth * $arf;
  $xmid = $width >> 1;
  $pmid = $patternwidth >> 1;
  $s0 = $xmid - $pmid;
  $s1 = $s0 + $patternwidth;
  $x0 = $xmid - ($minpatternwidth >> 1);
  $x1 = $x0 + $minpatternwidth;


  for ($row = 0; $row < $height; $row++):
	  $patternrow = $row % $patternheight;
	  for ($x = $s0; $x < $x1; $x++)
		  imagesetpixel($im, $x, $row, imagecolorat($pattern, $x - $s0, $patternrow));
	  for (; $x < $s1; $x++):
		  $x2 = findoffset($im, $map, $x, $row, $patternwidth, $arf, -1);
		  if ($x2 < $s0)
			  imagesetpixel($im, $x, $row, imagecolorat($pattern, $x - $s0, $patternrow));
		  else imagesetpixel($im, $x, $row, imagecolorat($im, $x2, $row));
	  endfor; 
	  for (; $x < $width; $x++):
		  $x2 = findoffset($im, $map, $x, $row, $patternwidth, $arf, -1);
		  imagesetpixel($im, $x, $row, imagecolorat($im, $x2, $row));
	  endfor;
	  for ($x = $x0 -1; $x > 0; $x--):
		  $x2 = findoffset($im, $map, $x, $row, $patternwidth, $arf, +1);
		  imagesetpixel($im, $x, $row,
			  imagecolorat($im, $x2, $row));
	  endfor;
  endfor;

  returnimage($im, $_POST['outputtype']);
}
else { ?><html>
<head><title>Make your own stereogram</title></head>
<body>
<h1>Make your own stereogram</h1>
<form enctype="multipart/form-data" action="" method="POST">
	<input type="hidden" name="MAX_FILE_SIZE" value="300000" />
	Background pattern: <input name="pattern" type="file" />
		<input type="radio" name="patterntype" value="png" checked />png
		<input type="radio" name="patterntype" value="gif" />gif
		<input type="radio" name="patterntype" value="jpeg" />jpeg
	<br />
	Profile map: <input name="map" type="file" />
		<input type="radio" name="maptype" value="png" checked />png
		<input type="radio" name="maptype" value="gif" />gif
		<input type="radio" name="maptype" value="jpeg" />jpeg
	<br />
	Output file type:
		<input type="radio" name="outputtype" value="png" checked />png
		<input type="radio" name="outputtype" value="gif" />gif
		<input type="radio" name="outputtype" value="jpeg" />jpeg
	<br />
	Depth range factor (between 0 and 1):
		<input type="text" name="arf" value=0.25 />
    <input type="submit" value="Send Files" />
</form>
</body>
</html>
<?php }?>

Link to Quake in 3D appears to be broken

The link (in the external links section) to Quake in 3D appears to reference a non-existent url. 69.109.230.40 (talk) 19:04, 13 September 2009 (UTC) F. Hollander, flieg@berkeley.edu

Just a thing i found out

I don't know if anyone has written about this but I was doing the thumb thing on the animated "dot" shark and I found the dots where following my thumb, I just wanted to point that out —Preceding unsigned comment added by 60.225.242.202 (talk) 03:13, 7 November 2009 (UTC)

Animated Shark Stereogram

I created an animated version of the shark stereogram from the article (showing the image twice, with the second frame offset by the pattern length) that shows the 3D effect without requiring the wall-eye view. Might be a helpful addition to those who can't do the wall-eyed view and are wondering how those autostereograms look like. -- Grumbel (talk) 00:06, 5 October 2010 (UTC)

Wow. That is most helpful. I think you should:

• Promote your image to wikimedia. See how the images on this article were actually uploaded to wikimedia: here for instance. Note how all autosteregram images are tagged to appear in this category page.
• Add your image to the 'Animated' section of the article with text explaining this wiggling form of stereogram.
  • Perhaps remove that CRT paragraph. There is no source for that
• Perhaps add your image to the 'how they work' section along with other 'visualization' images. The trouble is how to make the image appear without it being too annoying. Perhaps instead of embedding the image, add a text link in the text that reference it.

If you can't do this, when I have time I will. Fred Hsu (talk) 05:01, 5 October 2010 (UTC)

I placed Grumbel's "wiggle stereogram" in the article. Thanks for making it. Robert P. O'Shea (talk) 09:14, 3 February 2022 (UTC)

what is this?

THERE'S NOTHING THERE

NOT A SHARK OR ANYTHING!!!

is this a joke or something?

are people pretending to see this?

please explain. 82.46.111.137 (talk) 21:30, 19 January 2011 (UTC)

Great work

The use of images in this article is superb. One of the best use of them in Wikipedia, really. Great work by those who've spent time editing here. Good job guys. 98.162.244.83 (talk) 06:34, 9 April 2011 (UTC)

Viewing depth cues backwards

I realized reading this article that I perceive autostereogram depth cues backwards, causing me to interpret the images falling into the page instead of popping out (something like a hollowface). Although I can see the images, I often have difficulty identifying what they depict. With some effort I have managed to get fleeting glimpses of the intended depth cues and it has improved my recognizing subjects noticeably. I was wondering if anyone knows more about this phenomenon or has experienced this themselves. Does it warrant mention in the article? — Preceding unsigned comment added by 98.65.210.29 (talk) 15:08, 31 May 2011 (UTC)

You're probably using the wrong vergence, or viewing technique, for the image: wall-eyed (parallel) and cross-eyed. Hyacinth (talk) 02:21, 14 October 2012 (UTC)

FA review needed

There appear to be quite a few items here that should be brought to current FA standards so that a Featured article review can be avoided. External links needs to be pruned, the Terminology section is listy, most of the text is unsourced, and there are numerous MOS issues (WP:MOSNUM, faulty use of WP:ITALICS, poor image placement, and unformatted citations). I hope someone is able to deal with these issues. SandyGeorgia (Talk) 04:58, 5 December 2011 (UTC)

The article is insulting towards those of us who can't see the damn things

There's this insistence that 'the human brain' can perceive these. Well, mine can't, and it's just as human as anyone else's. More recognition that some people can see these, and some can't, would be a good thing. 96.231.17.131 (talk) 21:00, 25 September 2012 (UTC)

If one has two eyes, fairly healthy eyesight, and no neurological conditions which prevent the perception of depth then one is capable of learning to see the images within autostereograms. Hyacinth (talk) 09:43, 26 September 2012 (UTC)

Not true. 96.231.17.131 (talk) 15:25, 13 October 2012 (UTC)

Empty assertions are not that convincing. If what you say is not true is really not true, why don't you find an explanation and cite it. Hyacinth (talk) 01:58, 14 October 2012 (UTC)

This article is biased against those of us who cannot see the supposed images

NPOV may not quite be the best fit.

However, I think the article needs to respect that some people cannot see the images. At present, the article states that "If one has two eyes, fairly healthy eyesight, and no neurological conditions which prevent the perception of depth then one is capable of learning to see the images within autostereograms." which is not true and which is insulting. At present, the article refers to "the brain" and "the human brain" in ways that imply we are not human or we do not have functioning brains. 96.231.17.131 (talk) 15:36, 13 October 2012 (UTC)

The intro does not mention that some people are unable to see the supposed images. There are only a few pathologizing remarks in the "mechanisms for viewing" section. 96.231.17.131 (talk) 15:36, 13 October 2012 (UTC)

In what way is the statement "If one has two eyes, fairly healthy eyesight, and no neurological conditions which prevent the perception of depth then one is capable of learning to see the images within autostereograms" insulting? Some people find it insulting when they are told they will never be able to learn something, rather than being told that someday they could learn.

The introduction to the article on rock climbing does not state that some people may not be able to climb the supposed mountain. The introduction to the article on reading does not state that some people may not be able to read the supposed words. Hyacinth (talk) 02:05, 14 October 2012 (UTC)

For one thing, it pathologizes normal variation. For another thing, it legitimizes those who would berate us for not seeing the damn things, and who would constantly insist that we relax, look again, and get a worse headache, and who would blame us for not trying. (I had a teacher who did that.) 96.231.17.131 (talk) 19:15, 14 October 2012 (UTC)

I don't know if you're right or left-handed. But imagine you're left-handed and had been through attempts to force you to use your right hand, and now you come across an article saying that "[Any healthy person] is capable of learning to write right-handed," wouldn't that be insulting? (I am right-handed, and have some actual hand disabilities, and have been through attempts to make me write "normally" which caused a lot of pain at the time. In this case, both normal healthy variation and disabilities can prevent "normal" writing. In here, I'd just like some respect for the fact that normal healthy variation and impairments seem to keep people from being able to see the supposed images.) 96.231.17.131 (talk) 19:15, 14 October 2012 (UTC)

I have already removed a few references to the brain, but some may be necessary as vision is neurological. Hyacinth (talk) 02:05, 14 October 2012 (UTC)

"It is only our eventual perception of the embedded image that indicates that we do not see the form per se with our eyes superficially. Given how the image is constructed, it is impossible to fake the perception for it is our brains that create the fused representation we eventually see when we fuse the slightly different strips that were used to create the random dot pattern (Taylor 1991: 41)." Ione, Amy (2005). Innovation and Visualization: Trajectories, Strategies, and Myths, p.213. ISBN 9789042016750. Hyacinth (talk) 07:52, 30 October 2012 (UTC)

I think you need to decide if you are mad at the stereograms, mad at yourself, or mad at the article. Either way, you shouldn't be taking it out on editors. You need to decide if you think that stereograms are real or not. If you think they are real, you need to stop calling them "supposed". If you don't, Wikipedia is no place for conspiracy theories.

You can't blame other people for your problems. If someone asks you to climb a mountain and you choose to, who's fault is it if you fall off the mountain? If I ask you to read a normal postcard someone sent me and you choose to look at it in such a way that you give yourself a headache, who's fault is it?

If, on the other hand, you where in a situation like my father, who was hit every time he used his left hand, and you are being punished for not attempting to see stereograms, you need to realize that the problem is not with the stereograms (or handedness) but with the person doing the punishing and their beliefs about power and rights. Most parents today wouldn't accept their child being beaten for being left handed. Not because most parents support left handedness, but because most parents are against their children being hit by their teachers, for any reason. Hyacinth (talk) 05:30, 30 October 2012 (UTC)

OK, between your personal attack just above, and your improper use of rollback, I'm real close to taking you to ANI to ask them to remove your rollback privilege. ←Baseball Bugs ^{What's up, Doc?} carrots→ 07:10, 30 October 2012 (UTC)

You are more than close. Take this issue up on my talk page. Hyacinth (talk) 07:48, 30 October 2012 (UTC)

Advice

I find that the easiest way to see the picture in these "Magic Eye" things is to bring your nose almost up to it and try to look "in the distance", i.e. with your eyes parallel instead of focused. Then slowly pull away. One you figure out the technique, it's a snap. It's worth pointing out that what you'll see is merely the splotchy pattern of the picture with one or more seemingly 3-D items in that same pattern. In fact, you might come the same conclusion I did: "What's the big deal?" ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:14, 30 October 2012 (UTC)

I assume many people who are frustrated by the inability to see the images are frustrated by repeated attempts at explaining how to see them. Hyacinth (talk) 06:38, 30 October 2012 (UTC)

I suppose so. I didn't get it right away either. But the technique I described is how I was told to do it. The trick is to "relax" your eye muscles so that you're looking straight ahead instead of focusing on the picture. It might take a few tries. You have to pull it away really slowly, and if you keep your eyes straight ahead, it should eventually turn up. Once it does, you can actually kind of look at it in some detail. It's kind of nifty. But they're all pretty much alike after awhile. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:53, 30 October 2012 (UTC)

Re-reading it just now, I can see where it might seem a bit patronizing. I've modified it. You and the IP can let me know what you think, and recommend any further changes. I could imagine someone might say, "Some people can never see them." That's dubious, because anyone who has normal eyes might not see it today, but might see it tomorrow. ←Baseball Bugs ^{What's up, Doc?} carrots→ 07:02, 30 October 2012 (UTC)

OK, Hyacinth, you reverted without comment. Explain yourself. ←Baseball Bugs ^{What's up, Doc?} carrots→ 07:05, 30 October 2012 (UTC)

In fact, it looks like you used rollback. This is not an appropriate use of rollback. ←Baseball Bugs ^{What's up, Doc?} carrots→ 07:07, 30 October 2012 (UTC)

Speaking of lack of explanation: you provided no edit summary, and no explanation in your second comment above.

You may ask that I do something, but there's no need to demand.

One of the problems with "rollback" is that its right next to "undo", but there's nothing one can do when its clicked (no preview). Hyacinth (talk) 07:17, 30 October 2012 (UTC)

Undo was not appropriate either. I plead guilty to failing to post an edit summary. But I had already talked about it here. No explanation of the second comment... you mean about someone not seeing it today but might see it tomorrow? That was to pre-empt someone (like the IP) saying, "Some people never see them." They can't say "never", unless they can provide some sourcing as opposed to personal observation. ←Baseball Bugs ^{What's up, Doc?} carrots→ 07:22, 30 October 2012 (UTC)

One change is not an edit war.

Note that you had not already discussed your edit here. Your edit was made at 01:00, you commented on it here at 01:02.

By second comment I mean "This is not an appropriate use of rollback." Declaring something inappropriate is not the same as explaining why it is inappropriate. Hyacinth (talk) 07:30, 30 October 2012 (UTC)

Unable and incapable

I would compare seeing the images within stereograms with any other skill or ability. Unless one isn't able to do it for some reason, one is potentially able to do it. Saying that some people never will be able to do it for no reason, doesn't make sense. However, making the claim that an individual will never be able to practice or achieve a skill or ability for a reason, may make sense.

There is a difference between someone who doesn't know how to practice a skill or ability (unable) and someone who is incapable of achieving or learning a practice or skill. Lumping the two into the same category and claiming that it is offensive to distinguish the two is, at the least, counterproductive.

This distinction does not become offensive just because a person was forced to try a practice or skill or ability, though it may bother that person to be told it is easy to achieve. Most children are forced to learn how to read, and then forced to read. This doesn't make it offensive to say that most children are capable of reading. It certainly doesn't make it untrue.

As such I am removing the neutrality tag and the dubious tag. Hyacinth (talk) 23:16, 2 December 2012 (UTC)

Suggestions

Some things that could be done to improve this article:

• The term SIS needs to be explained. How can it be applied to "wallpaper autostereograms"? Overall the terms need to be clarified and cited. I believe contradictions exist between the Wikipedia articles covering stereograms and stereoscopy regarding terms.
• Per the section directly above (though the anonymous user doesn't say it), some of the references to "the brain" should be removed. It took out one instance from the introduction: "the brain must overcome" and changed it to "one must overcome" to imply that it is an act of will on the viewers part rather than an act of will on the part of the brain as a separate agent from the viewer.
• The section "How they work" would more accurately be titled "Types". The information on how they work should be separated.
• Similarly, the section "Mechanisms for viewing" would more accurately be titled "How they work". The information from what is currently titled "How they work" could be put here.
• Overall the organization of the article could improve. The introduction is somewhat unclear (for example it describes a "wallpaper stereogram" as formed from a repeating pattern and a random-dot stereogram as having "every pixel...computed from a pattern strip and a depth map", which may not be clear that they are both formed from repeating patterns. Ideally the article would discuss principles of vision behind (the construction and) viewing of stereograms as early as possible, then types of stereograms. While Wikipedia is not a how to, some people react very negatively to the initial difficulty viewing often encountered viewing autostereograms. If I remember correctly the early Magic Eye books gave little useful information, primarily advising one to stare at the images a long time. We, obviously, can provide more information than that without being a how to.

Hyacinth (talk) 02:26, 30 September 2012 (UTC)

FA standards

Just saw this come up at ANI, and had a look through. This doesn't seem to be up to current FA standards. In addition to the tags that are on it now, there are still some issues remaining that Sandy pointed out a few threads up. The big thing seems to be lack of citations, and there may be issues of comprehensiveness that should be examined, as well. Is there anyone who wants to work on this or should it be brought to WP:FAR? Mark Arsten (talk) 14:06, 30 October 2012 (UTC)

The tags aren't an issue (WP:JUSTDON'TLIKEIT). However, as I've pointed out it has organizational problems and related clarity problems. The article is being worked on.

What topics or information are missing? Hyacinth (talk) 19:15, 30 October 2012 (UTC)

Ok, if you're working on it, I won't bother filing an FAR. On ANI, Kiefer mentioned "It does not mention the work of Persi Diaconis on the Julesz conjecture." I'm sure he could give you more details/suggestions if you asked him. Mark Arsten (talk) 17:58, 31 October 2012 (UTC)

One would need to establish a link between the Julesz conjecture and autostereograms to say that the article "neglects...major facts or details". Hyacinth (talk) 21:34, 31 October 2012 (UTC)

It looks like since Sandy commented the external links have been pruned. I assume by "unformatted citations" inconsistent formatting was meant, and I believe I have just fixed that. It appears that there are not (and where not) any WP:MOSNUM issues. Hyacinth (talk) 22:36, 31 October 2012 (UTC)

I'm unable to verify or fix subjective complaints such as faulty use of italics (nothing on the list of "When not to use italics" at WP:ITALICS is here italicized), poor image placement ("I think we should hang the painting on this wall"--"I think we should hang it on this wall..."), and most of the text being unsourced without it being tagged or commented upon. Hyacinth (talk) 00:46, 1 November 2012 (UTC)

FAR needed

I pointed out issues a year ago; Mark Arsten expressed similar concerns a few months ago. This article is high on this list, and the issues have not been resolved. Please resolve all tags within the next few weeks: this article needs to be submitted to WP:FAR. SandyGeorgia (Talk) 16:26, 2 December 2012 (UTC)

Health

Is focusing this way for a prolonged period bad for your health? Or is it good eye exercise?

I want to second this very important question with an emphasis on the eye's physiological and brain's neurological healths points of view. From my personal experience stairing into these kind of images have two opposing effects. The first is perceived while one looks into them which is a relaxation of the eyes (in addition to some surprise and excitement of course) however the second opposing effect is more likely to be on the neurological side of HVS (Human Visual System) and is therefore more serious. I hope there is some medical research on the effects of wall-eyed perception on HVS's normal operations. Because it is expected that as the coordination between eye muscles, eye nervers, and image sysnthesis part of HVS is altered in some tricky way to fake HVS to create an illusive 3D image, it might result in corrupted feedback coordination issues in this highly sensitive part of the brain. This topic is important because any potential negative effects on the HVS, may have fatal (irreversible) results on human normal viewing and reading cababilities or evern worse it can trigger less known types of neural anomalities whose side effects are rarely encountred and therefore less known within the medical circles... I repeat: this is an important issue and must be seriously considered.

117.199.2.88 (talk) 12:53, 6 December 2012 (UTC) Chocoball 117.199.2.88 (talk) 12:53, 6 December 2012 (UTC)

Wikipedia is not for original research. OhNoitsJamie ^Talk 15:40, 4 November 2015 (UTC)

Why does "rastergram" redirect here?

Not mentioned in article. 109.157.79.50 (talk) 03:48, 9 January 2015 (UTC)

Why are all images wall-eyed?

The introduction mentions two different types of autostereograms, but ALL images with a type identifier are wall-eyed. Where are the cross-eyed images? Medinoc (talk) 20:49, 17 March 2016 (UTC)

See Commons:Category:Cross-eyed vergence autostereograms, specifically File:Mariposas autoestereoscópicas.JPG. Hyacinth (talk) 14:38, 28 June 2016 (UTC)

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Perceived location in front or in the background?

The following statements in the article seem to contradict each other:

"An image designed for wall-eyed viewing if viewed correctly will appear to pop out of the background, while if viewed cross-eyed it will instead appear as a cut-out behind the background and may be difficult to bring entirely into focus."

"This type of visualization is known as wall-eyed viewing, [...]. Because the two eyeballs converge on a plane farther away, the perceived location of the imaginary object is behind the autostereogram."

In my view, the second statement is correct, while in the first it should be the other way around.

--KaiKemmann (talk) 13:05, 17 March 2017 (UTC)

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too many WALL EYED only 1 CROSS EYED

As the title says, there is 95% of images in this article are wall eyed. Why only 1 image cross eyed, is there a problem with those? — Preceding unsigned comment added by Santropedro (talk • contribs) 23:25, 10 February 2018 (UTC)