When I receive mail I find it obnoxious when passing, curious people read the senders address and there is an out pour of obnoxious questions or comments - "Ohh Dr. Bushwhack, he really sends high bills, but he takes even the hopeless cases. I once had a coworker who ..., and why do you go there?"

To eliminate the problem the senders address on sensitive mail should be printed as a stereogram (link). With just a little training stereograms are easy to recognize, but you do have to stop and stare at them for a moment to see, nothing for the walk-by spy.
-- kbecker, Jun 18 2004

Examples of stereograms http://www.aceviper...3d_stariograms.html
I like the Dolphins. To the casusal viewer they look like a bunch of flowers; visual steganography. [kbecker, Oct 04 2004, last modified Oct 21 2004]

Make your own http://www.eyetrick...s/stereocreator.htm
[kbecker, Oct 04 2004, last modified Oct 21 2004]

Arty stereogram nudes http://www.starosta...showcase/inude.html
Luckily, I find it very easy to see stereograms [hippo, Oct 04 2004, last modified Oct 21 2004]

Text Stereogram http://www.lce.hut....ikalliom/stereo.txt
Particularly good example [Dub, Aug 23 2005]

c - source ;) http://www0.us.ioccc.org/2001/herrmann2.c
(The International Obfuscated C Code Contest ) [Dub, Feb 04 2006]

I think this problem has more to do with where you choose to open your mail. The Post Office, after all, is going to have something to say if you make the return address so difficult to read.
-- DrCurry, Jun 18 2004


ATM's could also use this to make sure info can't be seen from an oblique angle. You could opt to do your ATM business in stereogram, or not.
-- phundug, Jun 18 2004


[DrC] Where I live the senders address is usually on the outside, upper left corner on the front or top center on the back. You don't have to open the mail to see it. The post office usually doesn't care about the return address, only if something goes wrong with delivery.

Since I'm not retired or unemployed I cannot always choose where to grab my mail. A lot of it even goes to my workplace so my employer can forward it when I'm on an extended business trip.
-- kbecker, Jun 18 2004


I've seen software somewhere, I think, that makes those things out of text.

Has anyone built an electronic means to "decode" those stereograms? If so, the Post Office might want some.
-- half, Jun 18 2004


[half] see link for an online version. I don't know about any system to decode stereograms but the algorithm is known so a camera that has sufficient resolution to identify the dots with an attached computer should be able to do it.
-- kbecker, Jun 20 2004


I have NEVER managed to see one of those pesky things.
-- gnomethang, Jun 20 2004


they are easier to see on that make your own link.

gnome, put your eyes right up to the screen and go into daydream mode.
-- po, Jun 20 2004


Nope! Not even with my own name in it!
-- gnomethang, Jun 20 2004


you're not crossing your eyes obviously.
-- po, Jun 20 2004


Try the "parallel" first, and relax, relax, relax. It may help if you see a slight reflection of yourself on the screen. The point is that the angle adjustment of the eyes is on something further away than the screen. It gets better if the focus of the individual lenses is right on the screen, but that is a training issue.
-- kbecker, Jun 20 2004


The first is always the hardest, and I find it to be much easier with posters than on monitors.

You have to defocus your eyes just far enough so that one of the repeating patterns from each eye line up on top of eachother, then once they are lined up, stay there for just a bit. The image will gradually make itself out.

Usually it's about an inch or two of overlap. It helps to stay away from the edges of the pictures, usually.
-- RayfordSteele, Jun 22 2004


[kbecker] See [Text Stereogram] link... I like the idea that it'd be great to send a secret/subliminal message in the text... except if advertisers get hold of the idea, it'd be a nightmare.

[half] If you visit the link, and copy the text to an editor, it's pretty easy to see (excuse the unintentional pun) how it's done... The words are echoed across the paragraph (the text itself doesn't make sense, but it'd be neat if it did... See HB [Hidden Messages] inspired by this posting)
-- Dub, Aug 23 2005



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