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Comment by pablo1 | Hacker News Reader

Don't know much about stereograms, two general questions:

a) Is it possilbe to render color images this way? b) Is it possible to have the random dots not change all the time? E.g. When I don't move in this example, I dont see the need to draw new random dots. Also when moving sideways e.g. would it be possible to keep the dots where they are, relative to the world?

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It's possible to use color in that the dots don't have to be black and white, and don't have to be totally random. The way an autostereogram works is that there's a repetitively tiled base image (or vertical column repeated horizontally). The stereographic angle information is encoded in mutations of the repeating image. That base image can be anything (including a photo).

However, this color image will not correspond in any way to the 3D geometry of the scene. I don't know of any way to get color information to correspond to BOTH the 3D geometry and the stereographic information (without using two images).

In the Wikipedia article on autostereogram [1] there is an example of a chess set [2] where the 2D image directly corresponds to the 3D autostereogram image. It is apparently a type of wallpaper autosterogram, instead of random dot, which requires horizontal repetition for the effect to work.

[1] https://en.wikipedia.org/wiki/Autostereogram [2] https://en.wikipedia.org/wiki/Autostereogram#/media/File:Che...

Interesting! I think this is possible here because the 3D geometry is also horizontally repetitive.

That picture in particular has a really interesting parallax effect - view it in stereo and move your head around. For me, the back rank seems to shift a lot with head position, even though the image itself is (obviously) stationary.

Regular Magic-Eye pictures do this too, but to a much less noticeable degree.

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