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I have never before seen ASCII stereograms! https://hidden-3d.com/index.php?id=gallery&gallery=text

"the night" "I'm" "lost"

so glad I fell off the wagon right before getting on HN again. Much easier to make my eyeballs move this way.

There's a bit more:

STARING

By staring at the night

I'm lost

And I wonder where

My dreams disappeared

Wayne Myers

30th Dec, 2009

How are you seeing this?

You look beyond the writing so that your eyes start to slip out of focus on the text and give a double image. Like how if you look at your computer screen while having a finger in front of your eyes, you'll see a double image of your finger. But in this case you need to manage looking beyond the screen with no true object to focus on.

Once you manage that double vision, you adjust your focus until one eye's view shifts to the right far enough that the first column lines up with the second column. You can adjust your distance from the image to help with that. Once they line up, for me it feels like it almost snaps into place - at that point I can look around the 3D image without breaking lock on the lined-up view. You now have three readable columns plus two ghost-like half visible ones on each side, and those particular words stand out as if they're in front of the rest.

Ignoring the two 'ghost' columns:

'STARING' is in column 2

'By staring at the night' is in column 1

'I'm lost' is in column 2

'And I wonder where my dreams disappeared' is in column 3

'Wayne Myers 30th Dec, 2009' is in column 2

Obviously, all that text is in all columns. but those are the ones where it's been made to stand out in 3D. It also reads from top to bottom.

Thanks - took me ages to get this one. Ended up copying it into Notepad and then could see it. It's fun to edit the text while viewing it in 3D - you can cause more of the text to jump out of the page.

Yeah it seems like a really easy way to make stereoscopes, because you can just adjust the spaces! I kinda want to play around with making one myself.

I wasn't sure if you were just having trouble with this one, or if you didn't know about viewing stereoscopes at all.

Woah.

I use this method to compare two images or pieces of text, but instead of relaxing the view, I do it cross-eyed, because this removes the requirement that items from both documents can only be separated at max by the separation width of the eyes.

So for example today I was cleaning up a server, freeing up some space, and then made it send me a storage space summary. I compared that one with the one I always get sent at midnight, put them side by side, and compared them via the cross-eye method. Small differences are always noticeable.

I also consider it as my cheat in order to solve those puzzles where you have to find the differences between two images, it doesn't get any easier than this.

It's amazing that this shows our visual system constantly doing a type of low level computation to calculate our stereoscopic 3D vision, and that we can "exploit" this hidden computational power to easily find image differences.

I remember reading that this was actually how Pluto was discovered: Someone compared a lot of photographic plates with this method. To clarify: You can take two images of part of the sky a short time apart. Stars won't move, planets will.

For Pluto, for what I know, they did use the technique of taking two images of the sky at different times and looked at them through a machine, but instead of relying on stereoscopic vision, they switched back and forth between the two, everything that isn't the regular star background would be moving or blinking.

So, relying on movement perception.

I use this trick too for puzzles! Spotting on the fly the differences, makes for a great intro of the topic with people not aware of it!

This was a huge trend in the 90s that I missed out on, because for some reason I can only see the cross-eye versions, but all the books and posters you could buy were the straight-eye versions.

I'm confused? Don't they all require crossing your eyes? I've gone through about 20 on this site and "solved" them by crossing my eyes and locking the patterns together.

Most of autostereograms are meant to be seen wall-eyed, instead of cross-eyed [0]. With wall-eye, you shift the convergent point being what you're seeing, while with cross-eye you shift it before.

So it creates the exact opposite 3d. Watching a stereogram meant to be seeing wall-eyed, cross-eyeing you'll see an upside down 3d. Some stereogram are mean to be seen cross-eyed though, which is considered easier to see.

[0]: https://en.wikipedia.org/wiki/Autostereogram

It wont’t turn the image upside down, but the depth will be inverted, so what is meant to jut out at you will become a trough away from you.

"the depth will be inverted" better describes it indeed. Thanks clarifying it!

> With wall-eye, you shift the convergent point being what you're seeing,

Here "being" probably should have said "behind".

https://hidden-3d.com/stereogram_theory.php

Either can look in front or behind.

3DImka, who is being most of hidden-3d.com, is constantly pushing the boundaries of stereograms!

I highly recommend having a look at some of his best creations on deviant art [0], particularly his technic of matching outlines with the final 3d result [1], or his experiments with transparency [2].

[0]: https://www.deviantart.com/3dimka [1]: https://www.deviantart.com/3dimka/art/You-must-not-fool-your... [2]: https://www.deviantart.com/3dimka/art/8-Legs-Magical-Stereog...

I stared at this one for a long time: https://hidden-3d.com/index.php?id=gallery&pk=457 They use opposite colors for the foreground which makes it look opalescent and gray at the same time.

Ah the fading colours experiment! Interesting one! I'm still not grasping the efforts it takes to create those effects..

I find this effect somewhat unpleasant to look at though.

That transparency effect (in [2]) looks great.

Some very interesting stereograms here https://www.pakin.org/~scott/stereograms/

e.g.

https://www.pakin.org/~scott/stereograms/caged-creature.jpg

https://www.pakin.org/~scott/stereograms/straight-lines.png

https://www.pakin.org/~scott/stereograms/number-one.jpg

https://www.pakin.org/~scott/stereograms/spheres-cubes.jpg

https://www.pakin.org/~scott/stereograms/camping-tent.png

For the first time of my life, I managed to see it, thanks to this tutorial:

https://hidden3d.com/howto-view-stereograms/

As an aside, I really like the stereogram on that page. The background seems designed for the purpose, so the edges on the 3D object are actually outlined, rather than the general kind of stereogram where you just get the texture randomly applied to the object.

Ah, yes, a sailboat.

I could never see these, I always felt a little silly when the other kids were finding them so amazing. Turns out my left eye never really learned to collaborate. I was born with cross eyes and had the operation to straighten them out very young, but I guess it was too late and I was already wired to have a right dominant view. My left eye is basically one big peripheral spot to my vision. I still see movements in it but I need to look at stuff with my right eye to feel like I am "seeing" it.

My left eye also sees in a different focal length and hue of colours, it's more vibrant and things feel further away compared to my right (astigmatism?), I am sure that didn't help the collaboration.

Astigmatism is kind of a directional blur. If some lines look more blurry than others while looking at this image with one eye at a time, you may have it.

https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F...

I also have an astigmatism. Left eye is pretty dark and blurry, it makes parking a bitch because of poor depth perception. When I was a kid with a lot of effort I could see these, but not any more.

These were all the rage in the mid-nineties. The bookshops were full of image books with stereograms of dinos, cars, ships, etc. Suddenly it all died down and now it looks like a relict from a distant past, although it still is as cool as it was then.

Ah, this brings back memories!

A long time ago I maintained a fascination with this, during which I made an application to interactively explore a labyrinth using animated auto-stereograms.

If this tickles your fancies, you can find the code here: https://github.com/moses-palmer/InAmazing3D. Please keep in mind that it apparently hasn't been touched in ten years, and the project used Code::Blocks, so if you want to try it, you will probably have to create Makefiles. If you enjoy this kind of thing, it's worth it though, as you get to control a ball moving through a labyrinth!

Related: Displaying two different colors to each eye while stereoviewing produces what's called "impossible colors". I ran a small experiment on a game development forum once and it turns out about 50% of people see grey when shown opposing colors simultaneously, while the other half's brains can't decide what color they see and it fluctuates in a way similar to staring at the Sun (did that for about 20 seconds, lost center vision for a month, thankfully no permanent damage. Couldn't read text as each letter vanished as I looked at it!).

I can highly recommend this book (readable on internet archive, but also linked to Amazon on this sites books page) on (auto)stereograms:

https://openlibrary.org/works/OL3493694W/Stereogram

It has history about the very earliest computer generated dot stereograms, several of Salvador Dali's stereo paintings, close ups on insect faces, historic stereo photos and many other varieties and variations of 3D images.

Oh nostalgia just knocked the door :-)

I have somewhere in my library one of the Magic Eye books and I was a huge fan of stereograms back in the 90s. The moment you see your first stereogram you feel a strange sensation, like something has been unlocked in your mind.

Fellow HNers who haven't experienced this should dedicate some time and go down this nice rabbit hole ;-)

I also saw stereograms being used in scientfic papers as a tool for 3D visualization.

Sometimes a molecule 3D shape is crucial for the understanding its properties and how it bonds with other molecules.

How do you actually show a molecule's 3D shape on a LaTeX paper? ...Stereogram. :)

I had one of these books as a child! They are super fun.

The 3D objects in them can be crazy "high resolution", with a load of detail, and training your eyes to see them is magical

I think I can see stereograms, but I'm never sure - are they supposed to look like layers of shaped cutouts that pops in/out once you see them? I can see the 3D depth perceptions manifest, but it's always hard to distinguish what those outlines are representing exactly. Not sure if I'm just constantly underwhelmed by those, or I've not been seeing them properly.

No, if you can see it, I think you should be pretty sure. I just managed to see it the first time of my life, I was shocked, it's so amazing.

Cross-eyes videos are even better.

Most of them have an "answer" button on top you can click to see the 3d model you're supposed to see.

I have to ask: how to create this? E.g. from normal picture "encrypted" to like that?

I had a book with these patterns once. The last few pages explained how you could make them yourself. Basically you make grid of lines with repeating patterns, like XXYYZZXXYYZZXXYYZZ. Then at certain places you can either make the pattern longer or shorter, like XXYYZZXYYZZXXYYZZ, or XXYYZZXXXYYZZXXYYZZ. One of them makes it appear to come forward, the other backward (forgot which ones). You can remove/add more elements to make them appear further or closer away. I used to make this as a child on graphic paper with colored pencils. You cannot do that anymore with a job and children ;)

There's an app Stereogram Lab: https://hidden-3d.com/index.php?id=software

At one time there was a great ios app that could generate these images from any photo by cutting the background out. Long lost in the Apple 32bit purge. You could also draw images using your finger and it could generate the stereogram from that too.

I absolutely love this, when I was a child I have seen a book with those pictures and wanted to have one since then. It gives weird type of pleasure once you force your eyes to 'see'.. :)

An interesting experience is that I find it easier to look at these than a normal flat screen, maybe my nearsightedness plays a role. They also appear sharper than the flat screen.

Always wanted to see them, but I'm stereo blind ( ; ; )

The captcha!! I bet even today's AIs wouldn't be able to solve these.

obligatory pbf: https://pbfcomics.com/comics/magic-eyes/

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