<p>A Single Image Random Dot Autostereogram (&lt;a href="<a class="external free" href="https://en.wikipedia.org/wiki/Autostereogram">http://en.wikipedia.org/wiki/Autostereogram</a>" rel="nofollow"&gt;SIRDS&lt;/a&gt;) produced on an Apple Mac using the &lt;a href="<a rel="nofollow" class="external free" href="http://www.katsurashareware.com/pgs/sirds.html">http://www.katsurashareware.com/pgs/sirds.html</a>" rel="nofollow"&gt;Sirds Application&lt;/a&gt; by &lt;a href="<a rel="nofollow" class="external free" href="http://www.katsurashareware.com/">http://www.katsurashareware.com/</a>" rel="nofollow"&gt;Katsura Software&lt;/a&gt;. If you use Windows - and want to have a go yourself - there are some free applications and Photoshop plugins available for your OS if you search for them.
</p><p>The image is a so called "wall eye" type (as opposed to a "cross eye" type). To see the "hidden" 3D image, look distantly beyond the surface of the image until the repeated pattern re-locks. 
</p><p>If it works for you, you should see a face framed in a square window. (Experiment with different sizes - "&lt;a href="<a rel="nofollow" class="external free" href="https://www.flickr.com/photos/dominicspics/3386116232/sizes/o/">https://www.flickr.com/photos/dominicspics/3386116232/sizes/o/</a>"&gt;ALL SIZES&lt;/a&gt;" - of the image if you have problems.)
</p><p>The Depth Map that the image is based on can be seen &lt;a href="<a rel="nofollow" class="external free" href="https://www.flickr.com/photos/dominicspics/3385307781/">https://www.flickr.com/photos/dominicspics/3385307781/</a>"&gt;here&lt;/a&gt;.
</p><p>The base repeating Random Dot image that the image is based on can be seen &lt;a href="<a rel="nofollow" class="external free" href="https://www.flickr.com/photos/dominicspics/3385498341/">https://www.flickr.com/photos/dominicspics/3385498341/</a>"&gt;here&lt;/a&gt;.
</p><p>There is a very detailed technical description of autostereograms, their geometry, and algorithms at &lt;a href="<a rel="nofollow" class="external free" href="http://www.techmind.org/stereo/stech.html">http://www.techmind.org/stereo/stech.html</a>" rel="nofollow"&gt;www.techmind.org/stereo/stech.html&lt;/a&gt;
</p><p>Some nice galleries &lt;a href="<a rel="nofollow" class="external free" href="http://www.colorstereo.com/">http://www.colorstereo.com/</a>" rel="nofollow"&gt;here (colorstereo.com)&lt;/a&gt; and &lt;a href="<a rel="nofollow" class="external free" href="http://hidden-3d.com/">http://hidden-3d.com/</a>" rel="nofollow"&gt;here (hidden-3D.com)&lt;/a&gt;.
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Part of a &lt;a href="<a rel="nofollow" class="external free" href="https://www.flickr.com/photos/dominicspics/sets/72157615858386181/">https://www.flickr.com/photos/dominicspics/sets/72157615858386181/</a>"&gt;set of photos&lt;/a&gt; exploring illusions of depth and space.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/64097751@N00">Dominic Alves</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/dominicspics/3386116232/">Illusion of Depth and Space (22/22) - Framed Face Autostereogram</a>